Latest Avalanche Advisory Posted on the City and Borough of Juneau Websitehttp://www.juneau.org/avalanche/index.phphttp://www.juneau.org/avalanche/index.phphttp://www.juneau.org/avalanche/index.php
The National Weather Service Forecasts- TODAY...RAIN. HIGHS AROUND 41. EAST WIND 10 TO 20 MPH. TONIGHT...RAIN...HEAVY AT TIMES. BECOMING WINDY. LOWS AROUND 40. SOUTHEAST WIND INCREASING TO 20 TO 30 MPH WITH GUSTS TO AROUND 50 MPH IN THE EVENING. CHANCE OF RAIN 100 PERCENT. SUNDAY...RAIN...WINDY. HIGHS AROUND 46. SOUTHEAST WIND 15 TO 25 MPH WITH GUSTS TO 35 MPH IN EXPOSED LOCATIONS. CHANCE OF RAIN 90 PERCENT. With several inches of snow in the last 24 hours up high accompanied by warming, crossloading winds, and continued precipitation avalanche danger is high at this time. During the next 24 to 48 hours we will see heavy precipitation at times, accompanied by 5+ degree warming trend. Slide sizes will continue to increase as well until/unless warming turns the precipitation to the form of rain. ]]>Sat, 27 Mar 2010 00:00:00 -0800http://www.juneau.org/avalanche/index.phphttp://www.juneau.org/avalanche/index.php
The National Weather Service Forecasts- TODAY...RAIN SHOWERS. WINDY. HIGHS AROUND 47. EAST WIND 15 TO 25 MPH. WIND GUSTS TO 45 MPH IN THE MORNING. TONIGHT...MOSTLY CLOUDY WITH A 40 PERCENT CHANCE OF RAIN. LOWS AROUND 40. EAST WIND 10 TO 20 MPH. MONDAY...MOSTLY CLOUDY WITH A 40 PERCENT CHANCE OF RAIN SHOWERS. HIGHS AROUND 45. EAST WIND 15 MPH. With close to a foot of snow in the last 48 hours up high accompanied by very strong crossloading winds, several degrees of warming throughout today and continued precipitation avalanche danger is high at this time. Slide sizes will continue to increase as well until/unless warming turns the precipitation to the form of rain. ]]>Sun, 28 Mar 2010 00:00:00 -0800http://www.juneau.org/avalanche/index.phphttp://www.juneau.org/avalanche/index.php
The National Weather Service Forecasts- TODAY...SNOW AND RAIN IN THE MORNING...THEN RAIN IN THE AFTERNOON. SNOW ACCUMULATION UP TO 1 INCH. SNOW LEVEL 200 FEET RISING TO 1500 FEET IN THE AFTERNOON. HIGHS AROUND 37. SOUTHEAST WIND 10 MPH. TONIGHT...RAIN. LOWS AROUND 36. SOUTHEAST WIND 10 MPH. NEW YEARS DAY...RAIN LIKELY. HIGHS AROUND 39. LIGHT WINDS. SATURDAY NIGHT...CLOUDY. CHANCE OF RAIN. LOWS AROUND 34. LIGHT WINDS. We received quite a bit of new snow in the last few days. Over a foot on several weather stations around town. We received .8" of moisture in the last 24 hours in the urban path areas. This is a orange flag indicator as to the loading rate. The winds have averaged above 10 mph for over 36 hours on Mt Roberts, with long periods in the 20's and into the 30's. Winds have averaged above 25mph during that same time on Douglas Island with gusts well into the 40's. These are red flag indicators of windloading. Temperatures have risen an average of 8 degrees during the last 36 hours. Accompanied by the heavy snow and winds this is another red flag indicator of direct action avalanche conditions. Yesterday some slabs were pulling loose and pockets of instability were easily skier triggered. Shooting cracks were evident in places and the snowpack sounded hollow walking through deeper wind drifts. This is #4 of the 5 red flag indicators for direct action avalanches. The last indicator for direct action avalanches is simply viewing recent avalanches. As daylight comes on today it will be interesting to see if we see much in the way of natural avalanching currently. Todays moisture models were lowered. Last night we did not receive nearly as much moisture as predicted. So although we are seeing 4 of the 5 red flag indicators it may take a little longer to go into a natural cycle. Todays temperatures are predicted to rise to 37 at sea level with as much as .31 inches of moisture throughout the day. Tomorrow's temperatures are expected to rise to 39 with as much as .81 inches of moisture. We should start to see natural avalanche activity already but in the next 2 days the slopes will have a great deal of additional stress placed on them. Although much of the snow this season has been light and simply blown off the faces of Mt Roberts and Mt Juneau, this is quite deceiving. There are several natural gullies and ridges on the slopes. These features gather snow with up channel winds in the form of cross loading. So in most areas there is only 1 to 2 feet of snow, yet in these loaded areas the possibility exists for snow depths in excess of 10'. As the rain line rises through the elevations watch to see additional activity as the rain places stress on an already weak snowpack. If the rain line stays high and heavy rains persist for longer periods of time the possibility exists for the water running down the hill to simply undercut the snow and release if from steep rocky faces and areas with fewer anchors. DOT will be shooting Thane Road this morning to see if they can pull down some of the deeper weak layers of instability we have seen through the early part of the season. The goal is to releive the stress in the snowpack during a time when the road is closed and access in controlled. We may or may not see large slides. But the reality is simply shooting the slope faces will impact the weak layers and help to build long term stability in the snowpack for later in the season. Thats not to say it still could not avalanche. But the goal is to reduce the depth and size of that avalanche should it occur during non controlled times. Avalanches today are not expected to he huge. Yet in longer steeper slopes quite a bit of snow could move. Extreme caution is recommended anyplace in the backcountry over the next 48 hours. AVALANCHE DANGER IS HIGH AT THIS TIME]]>Fri, 31 Dec 2010 00:00:00 -0900http://www.juneau.org/avalanche/index.phphttp://www.juneau.org/avalanche/index.php
The National Weather Service Forecasts- TODAY...RAIN SHOWERS...MIXED WITH SNOW SHOWERS IN THE MORNING. SNOW ACCUMULATION UP TO 2 INCHES. SNOW LEVEL RISING TO 800 FEET THROUGH THE DAY. HIGHS AROUND 38. SOUTHEAST WIND 15 MPH...THEN SHIFTING TO THE SOUTHWEST IN THE AFTERNOON. TONIGHT...RAIN. LOWS AROUND 34. SOUTHWEST WIND 10 MPH SHIFTING TO THE SOUTHEAST LATE. FRIDAY...SNOW IN THE MORNING. RAIN THROUGH THE DAY. SNOW ACCUMULATION UP TO 2 INCHES. SNOW LEVEL 1300 FEET IN THE MORNING. HIGHS AROUND 39. SOUTHEAST WIND 10 MPH SHIFTING TO THE SOUTHWEST IN THE AFTERNOON. FRIDAY NIGHT...RAIN. LOWS AROUND 37. SOUTHEAST WIND 10 TO 15 MPH. We have received over 25mm of precipitation at tram summit levels in the last 24 hours. Temperatures have risen over 7 degrees during that time and are now at 0 at tram summit elevations of 1800'. While the Eaglecrest summit is -1, Mid Mountain Temperatures at Eaglecrest are showing 32F and also climbed by over 12 degrees in the last 24 hours. We gained 18cm of snow with 17mm of precipitation during the first part of the storm from 9am yesterday to midnight. Since that time we have added an additional 9mm or Precipitation with a total snowpack loss of 1cm. This is showing us placing a block of heavy wet snow on the looser lighter snow in place pre storm and even at the beginning of the cycle when temps were cooler. Winds from 10-30 mph were also present during out last 24 hour snowfall. This shows us the ability for great loading. Danger levels are HIGH at this time We are expecting over .7" of rain in the next 24 hours. Quite a bit of which will come in as snows at our upper elevations. Experimental forecasts show that we may receive as much as 2.8" of moisture before Sunday morning. This is going to place an incredible amount of stress on the snowpack. During the next 36 hours temps are predicted to continue to rise. We are not expecting nearly as much nightime cooling over the next few days as well. Avalanche Danger is HIGH. Avalanche sizes and the chances of an avalanche will continue to grow for the next 24 hours at least! Pretty much all the signs are present for a dangerous day in the mountains and things are not going to get any better in the next 24-48 hours. Backcountry Travel is NOT recommended. Please be aware of dangerous trails such as the Flume and Perseverance Trail. Even accessing trails such as the Dan Moeller can be hazardous during times of avalanche danger. ]]>Thu, 20 Jan 2011 00:00:00 -0900http://www.juneau.org/avalanche/index.phphttp://www.juneau.org/avalanche/index.php
The National Weather Service Forecasts- TODAY...RAIN. HIGHS AROUND 39. SOUTHEAST WIND 10 TO 15 MPH. TONIGHT...RAIN...HEAVY AT TIMES. LOWS AROUND 37. SOUTHEAST WIND 10 TO 15 MPH. SATURDAY...RAIN...HEAVY AT TIMES. HIGHS AROUND 40. SOUTHEAST WIND 10 TO 20 MPH. SATURDAY NIGHT...RAIN LIKELY. LOWS AROUND 35. SOUTHEAST WIND 10 TO 20 MPH. Temperatures have risen by 3 degrees in the last 24 hours. We have received .6" of rain at Sea Level during that time. Mt Roberts showed .5" of rain during that same time. Non of this precipitation in the last 24 hours has been in the form of snow with the possible exception of the top few feet of the mountain. We have seen quite a bit of settlement and consolidation in the upper snowpack in the last 24 hours. So overall even though avalanche danger is HIGH at this time do to large precipitation volumes, the size of the possible new snow surface avalanches is shrinking. Natural avalanches are likely and human triggered avalanches are probable. Especially in steep open convex slopes, with fewer anchors, where there is a lot of stress in the snowpack already in the form of creep. Experimental forecast models still show as much as 2.2" of additional precipitation in the next 48 hours. This continues to eat away at the bonds in the snowpack. This makes the frozen ice cube in place turn into a slurpee with a great deal of free moisture present. The precipitation is absorbed by the snowpack and it starts by adding weight and stress to the surface layers. As time persists the moisture continues to percolate through the pack. Once percolation has reached full depth and the snowpack has developed drainage channels to process the water the danger level could start to fall a little. But until that drainage has reached full depth we are continuing to add weight and stress to multiple weak layers deeper in the snowpack that have been lying dormant for some time. Rains are fairly heavy today and tomorrows high will once again be 39 degrees. We are predicted to receive as much as one inch of rain today and up to another 1.6" of rain during Tomorrow. 1.6" of rain in 24 hours would be the most stress we have placed on the snowpack in quite some time. Should avalanches happen in the older weak layers sizes could be greater in some areas were winds have deposited additional snows over the course of the winter. As we continue through this storm cycle the longer these warm temps and heavy rains persist the more we need to be concerned of the deeper weak layers in place until drainage in the snowpack is established. Remember to use extreme caution in the mountains until these precip rates and temps start to fall. Avalanche Transceiver, Probe, Shovel, and Partner. Dont leave home without them! There have been over 5 avalanche fatalities in North America in the last week. Most of which took place during times of Considerable and High Avalanche Danger. Remember when conditions are not favorable, scale back, be conservative and LIVE TO PLAY ANOTHER DAY!]]>Fri, 21 Jan 2011 00:00:00 -0900http://www.juneau.org/avalanche/index.phphttp://www.juneau.org/avalanche/index.php
The National Weather Service Forecasts- TODAY...WINDY. RAIN...HEAVY AT TIMES. HIGHS AROUND 40. SOUTHEAST WIND 20 TO 30 MPH DIMINISHING TO 10 TO 20 MPH IN THE AFTERNOON. TONIGHT...RAIN. SNOW LEVEL 1400 FEET. LOWS AROUND 35. SOUTH WIND 10 TO 20 MPH. SUNDAY...RAIN LIKELY. SNOW LEVEL 800 FEET INCREASING TO 1300 FEET IN THE AFTERNOON. HIGHS AROUND 40. SOUTHEAST WIND 10 TO 15 MPH. SUNDAY NIGHT...RAIN. LOWS AROUND 36. SOUTHEAST WIND 15 TO 20 MPH. We have received 1.5" of precipitation in the last 12 hours and 2" of rain in the last 36 hours overall. During the last 20 hours we have received 10cm of new snow at tram summit elevations and some additional accumulation above that elevation. But most of this moisture came in the form or rain or rain saturated snows. Eaglecrest saw a little more in the form of snow with 6" of new in the last 20 hours at the UAS snow study plot mid mountain but densities remain extremely high. We are expecting as much as another 1.5" of rain in the next 24 hours. This is continuing to add weight and stress to the snowpack rapidly. With most of this moisture coming it the form of rain it continues to eat away at the bonds in the snowpack in the surface layers. This continues to erode the bridges that have been supporting the snowload over old weak layers in place. The longer the rain persists and the higher the accumulation rates the more stress that is being added to the deeper weak layers in place. Avalanche Danger is HIGH at this time. Upper mountains saw quite a bit of new snow in the last 24 hours... with slabs as deep as 2' in places. We went through a large natural avalanche release cycle today. Thane Road, The Berhands Path, The White Path, Chop Gulley (above the flume) all had natural avalanches today. Most slides were class 2+. Even though we have releived a great deal of stress in these areas and removed a lot of mass from the slopes, The danger is present for secondary slides in the same areas. Without viewing the starting zones to know how much mass has cleaned out it is hard to predict if we have seen the worst of it. Temperatures are predicted to fall overnight. Moisture accumulation rates are predicted to fall after midnight. After that time the snowpack will start to solidify again. But danger will be present for a while longer until the moisture is fully absorbed and bonding has occured. This is a good time to remind ourselves of protocols during times of HIGH avalanche danger. Avoid trails such as the Flume and Perseverance Trail. Limit your travels down Thane Road and when doing so notify someone you are on the way, then check in with them once your cleared. Do not park along Thane road to walk the beaches. Do not walk or jog along Thane Road. Limit your time spent in the Urban Avalanche Zones from the Berhands Subdivision to the White Subdivision. Go out to dinner, see a movie, perhaps even spend an evening at a friends house. Now is a good time to avoid being in the area of danger. Backcountry Travel is Not Recommended. Remember, Avalanche Transceiver, Probe, Partner, Shovel are the basic tools to avalanche rescue. You should not be in Avalanche Terrain without them. ]]>Sat, 22 Jan 2011 00:00:00 -0900http://www.juneau.org/avalanche/index.phphttp://www.juneau.org/avalanche/index.php
The National Weather Service Forecasts- TODAY...INCREASING CLOUDINESS IN THE MORNING WITH RAIN DEVELOPING IN THE AFTERNOON. HIGHS AROUND 41. SOUTHEAST WIND 10 TO 15 MPH. TONIGHT...RAIN. LOWS AROUND 35. SOUTH WIND 10 TO 15 MPH. MONDAY...RAIN LIKELY. SNOW LEVEL 1200 FEET. HIGHS AROUND 40. SOUTHEAST WIND 10 TO 15 MPH. MONDAY NIGHT...RAIN. LOWS AROUND 36. SOUTHEAST WIND 10 TO 15 MPH. The Mount Roberts Tram Weather Station recorded 2.3" of precipitation in the last 48 hours. We have seen over 4" of precipitation in the last 6 days. Quite a bit of this precipitation has been in the form of rain. Even at tram elevations what could have been over a meter of snow ended up only delivering 44cm and after settlement over the 6 days with the warm temps and rain that only left a total of just over 30cm of total snow depth. Every few feet of elevation right now is making a large difference in snow depth. Yesterday where weather stations were only snowing 6" of new snow we were able to find over 3 times that much just a few hundred feet higher. Every elevation and aspect has slightly different layering and weak layer placement at this time do to temp differences, winds, and amount of rain/snow received. Yesterday morning we went through a rather wide spread natural avalanche release cycle. This can be good in removing weak layers and yet shows us that the weak layers are widespread throughout the region. Although we had many slides, many slopes have still not slid and have the same possible weakness present. Most of yesterdays avalanches appeared to be running on the innerface between two storm cycles. Temperatures dropped night before last and we placed dry snow on top of the rain wetted surface in place. The loading rates were VERY high. As we continued to load the dry snow on a greasy weak layer, temperatures were warming. So we placed a block of snow on top of a weak layer of champaign glasses that were resting on a greasy slurpee. As this rapid loading continued it was only a matter of time before we started to see slope failure. Avalanches were seen in the White Path, The Berhands Path, Thane Road, and Chop Gulley above the Flume Trail. Natural releases were also sighted at Eaglecrest, Mt Troy, Showboat Ridge, Mt Ben Steward. Natural activity was widespread. We were not able to view starting zones in the urban avalanche zones therefore it is difficult to say if we have cleaned out all the area of weakness or only part of the slope avalanched. Also there are weak layers deeper in the snowpack that are still questionable. So even if we cleaned out the upper weak layers we could still see avalanche activity in the form of secondary slides from the lower layers in place. Temps are cooling a bit over the next 24 hours. Precipitation rates have slowed greatly. This should give the snowpack time to settle and bond while adjusting to the new weight placed on it in the last 7 days. Temperatures and Danger levels remain HIGH today but should start falling lower in the next few days. Time is our friend. Be patient and give the snow that extra day to bond before venturing out into the backcountry. This is a good time to remind ourselves of protocols during times of HIGH avalanche danger. Avoid trails such as the Flume and Perseverance Trail. Limit your travels down Thane Road and when doing so notify someone you are on the way, then check in with them once your cleared. Do not park along Thane road to walk the beaches. Do not walk or jog along Thane Road. Limit your time spent in the Urban Avalanche Zones from the Berhands Subdivision to the White Subdivision. Go out to dinner, see a movie, perhaps even spend an evening at a friends house. Now is a good time to avoid being in the area of danger. Backcountry Travel is Not Recommended. Remember, Avalanche Transceiver, Probe, Partner, Shovel are the basic tools to avalanche rescue. You should not be in Avalanche Terrain without them. ]]>Sun, 23 Jan 2011 00:00:00 -0900http://www.juneau.org/avalanche/index.phphttp://www.juneau.org/avalanche/index.php
The National Weather Service Forecasts- TODAY...RAIN. BREEZY. HIGHS AROUND 43. SOUTHEAST WIND 15 TO 25 MPH. GUSTS TO 35 MPH IN THE AFTERNOON. TONIGHT...RAIN. BREEZY. LOWS AROUND 36. SOUTHEAST WIND 15 TO 25 MPH. GUSTS TO 35 MPH IN THE EVENING. THURSDAY...RAIN. HIGHS AROUND 38. SOUTHEAST WIND 10 TO 15 MPH. THURSDAY NIGHT...RAIN AND SNOW. LOWS AROUND 33. SOUTHEAST WIND 10 MPH. Temperatures have risen slightly in the last 24 hours. We received 22mm of moisture(remember 25.4 is one inch) in the last 24 hours. We are predicted to receive more than another inch of precipitation in the next 24 hours. Most of the surface weakness is limited to very small slides and after yesterday we should see limited activity with these smaller slides. Today is the warmest days we have seen since Dec 7th. As we continue to see these warm temps and moderate rains we are eating at the bonds solidifying the snow in place. As we continue this long warm wet spell this moisture adds weight and stress to the snowpack and continues to eat at the bonds deeper and deeper in the snowpack the longer the conditions exist. Last week we cleaned a lot of the weak layers in place off the mountains especially at lower elevations. As this condition persists it becomes more difficult to time avalanches and determine what layer they might run on. Be aware that although we do not have much snow in the urban zones down low, and although we cleaned a lot of weak layers out of the pack, the danger of avalanche is HIGH today. Natural avalanches are likely and human triggered avalanches are more than likely. ]]>Wed, 02 Feb 2011 00:00:00 -0900http://www.juneau.org/avalanche/index.phphttp://www.juneau.org/avalanche/index.php
The National Weather Service Forecasts- TODAY...RAIN. HIGHS AROUND 43 EARLY IN THE DAY. SOUTHEAST WIND 10 TO 20 MPH BECOMING LIGHT AND VARIABLE LATE IN THE AFTERNOON. TONIGHT...RAIN OVERNIGHT WITH A CHANCE OF SNOW LATE. SNOW ACCUMULATION UP TO 1 INCH. LOWS AROUND 32. NORTHEAST WIND 10 MPH SHIFTING TO THE NORTHWEST LATE. FRIDAY...SNOW AND RAIN LIKELY. SNOW ACCUMULATION UP TO 1 INCH. HIGHS AROUND 35. LIGHT WINDS BECOMING SOUTH 10 MPH IN THE AFTERNOON. FRIDAY NIGHT...RAIN AND CHANCE OF SNOW. LOWS 27 TO 33. SOUTHEAST WIND 10 MPH. We have reveiced 35mm of precipitation in the last 48 hours (about 1.4") Temperatures hit two month highs during that time. Avalanche Danger is currently HIGH. Temperatures fell by 2 degrees in the last 18 hours and precipitation rates are falling considerably. Temperatures are predicted to remain quite high today. As we give this rain time to drain out of the snowpack we will start to see a cooling trend in the temps throughout the next 24 hours that should give us near 8 degrees of additional cooling. As the snowpack looses its free moisture and continues to cool stability will increase. Danger levels are predicted to fall throughout tonight and in to tomorrow. Time is your friend right now. Remember the danger levels are still HIGH Today. ]]>Thu, 03 Feb 2011 00:00:00 -0900http://www.juneau.org/avalanche/index.phphttp://www.juneau.org/avalanche/index.php
The National Weather Service Forecasts- TONIGHT...RAIN. LOWS AROUND 36. SOUTHEAST WIND TO 15 MPH. THURSDAY...RAIN. HIGHS AROUND 40. SOUTHEAST WIND 10 MPH. THURSDAY NIGHT...RAIN. LOWS AROUND 33. SOUTHEAST WIND 10 TO 15 MPH. It was clear and cool late last week for several days. This comes following a week of rains to summit elevations. The lower snowpack is quite solid in place. Saturday we received almost 4" of new snow at upper mountain elevations. Monday we were able to see that this 4" had created slab formations in our urban starting zones. Some of these slabs failed naturally and several are still hanging. As we went through last night and into today the avalanche danger rose as we started to place this cold new snow on the few weak shallow slabs that are in place. Even without the presence of the slabs and weak layer, as this storm comes in accompanied by warming temps over the next few days danger levels are expected to rise. Temperatures have warmed by 5 degrees in the last 23 hours. During that time we have received 27mm of precipitation which in turn left about 28 cm of snow.(nearly a foot at tram summit) Winds out of the south (165 degrees) have been cross loading our slopes with average speeds of about 15 knots. Currently temps at tram summit level are -1. We are expecting as much as another 5 degrees of warming in the next 24 hours during which time we are predicted to receive about ½” of precipitation. If this stays as snow up high until tomorrow am that could be as much as another 6” of snow. If it turns to rain sooner you will have less snow and higher possibility of slides. Between now and tomorrow pm you should see some natural avalanche activity. This upside down snowpack will want to releive itself off of trees, rocks, and steep open pitches. Cornices will be forming weak and dropping off during the warm loading trend. Slide sizes are not expected to be huge yet we should start to see some activity as this system continues throughout today and into tomorrow. Remember in the backcountry always bring your transceiver, probe, shovel and partner. Limit exposure to avalanche paths in the community. Avoid avalanche zones as much as possible during periods of HIGH and EXTREME danger Be safe and enjoy the new snow today. ]]>Wed, 09 Feb 2011 00:00:00 -0900http://www.juneau.org/avalanche/index.phphttp://www.juneau.org/avalanche/index.php
The National Weather Service Forecasts- TODAY...RAIN. HIGHS AROUND 40. SOUTHEAST WIND TO 15 MPH. TONIGHT...RAIN. LOWS AROUND 34. SOUTHEAST WIND TO 15 MPH. FRIDAY...RAIN. SNOW LEVEL 1000 FEET AND RISING BY AFTERNOON. HIGHS AROUND 38. SOUTHEAST WIND 10 TO 15 MPH. FRIDAY NIGHT...RAIN. LOWS AROUND 34. SOUTHEAST WIND 10 TO 15 MPH. It was clear and cool late last week for several days. This comes following a week of rains to summit elevations. The lower snowpack is quite solid in place. Saturday we received almost 4" of new snow at upper mountain elevations. Monday we were able to see that this 4" had created slab formations in our urban starting zones. Some of these slabs failed naturally and several are still hanging. As we went through Tuesday and into Wednesday the avalanche danger rose as we started to place this new snow on the few weak shallow slabs that are in place. Even without the presence of the slabs and weak layer, as this storm comes in accompanied by warming temps over the next few days danger levels are expected to rise. We have seen a 7 degree temperature rise over 36 hours and are expecting a few more degrees of warming throughout the day today. This is a Moderate to Considerable warming trend. Winds have averaged 10-25 for the last 36 hours and were much higher on Douglas Island. These are moderate to considerable windloading conditions. We have seen 70mm of precipitation in the last 36 hours(roughly 2.4). The first 49mm of precipitation left 50cm of new snow at tram summit elevations. The last 20mm of moisture although near freezing temps(+1)translated into no new snow accumulation. This is a HIGH loading rate and as you can see from the last of the precip coming in the form of rain is placing quite heavy dense snow on top of looser lighter snows up high. Forecast precip models have been reduced slightly this am. With the continued precipitation and increase of another 2 degrees of temp on top of the weak layer and upside down slab in place AVALANCHE DANGER IS HIGH AT THIS TIME. Please avoid spending time in Avalanche Zones such as the Flume Trail, Perseverance Trail. Please avoid walking or jogging along Thane Road through avalanche paths. Limit your danger by limiting your exposure. Please remember when traveling in the backcountry dont leave home without your avalanche transceiver, probe, and shovel as well as a well with a trained partner. ]]>Thu, 10 Feb 2011 00:00:00 -0900http://www.juneau.org/avalanche/index.phphttp://www.juneau.org/avalanche/index.php
The National Weather Service Forecasts- TODAY...BREEZY...RAIN. SNOW LEVEL 1400 FEET. TEMPERATURES AROUND 40. SOUTHEAST WIND 15 TO 25 MPH DECREASING TO 10 MPH IN THE AFTERNOON. TONIGHT...RAIN. SNOW LEVEL 1400 FEET LATE. LOWS AROUND 34. SOUTHEAST WIND 10 TO 15 MPH. SATURDAY...RAIN. SNOW LEVEL 1100 FEET. HIGHS AROUND 39. SOUTHEAST WIND 10 MPH. SATURDAY NIGHT...RAIN LIKELY. LOWS AROUND 32. SOUTHEAST WIND 10 TO 15 MPH. It was clear and cool late last week for several days. This comes following a week of rains to summit elevations. The lower snowpack is fairly solid in place. It has seen quite a bit of rain and developed drainage down low. Up high it remains frozen and solid. Last Saturday we received almost 4" of new snow at upper mountain elevations. Monday we were able to see that this 4" had created slab formations in our urban starting zones. Some of these slabs failed naturally and several are still hanging. As we went through Tuesday and into Wednesday the avalanche danger rose as we started to place additional new snow on the few weak shallow slabs that are in place. Even without the presence of the slabs and weak layer, as this storm cames in accompanied by warming temps over the last few days danger levels rose quite a bit. We have seen a 7 degree temperature rise over the last 60 hours and are expecting it to remain warm throughout the day today. This was a Moderate to Considerable warming trend. Winds have averaged 10-25 for the last 60 hours and were much higher on Douglas Island. These are moderate to considerable windloading conditions. We have seen 87mm of precipitation in the last 48 hours(roughly 3.4"). The first 49mm of precipitation left 50cm of new snow at tram summit elevations. The last 38mm of moisture although near freezing temps(+1)translated into no new snow accumulation and settlement of nearly 10cm. So although the snows came in at under 10% densities you can see now the overall densities averages are nearer to 18%. To get that average you can assume something like the bottom half is 10-15% density and the top half might be like 23-28% Density. The weak layer is present and the mousetrap has been set. You have a rather large brick sitting on a weaker layer. This is a HIGH loading rate and as you can see from the last of the precip coming in the form of rain is placing quite heavy dense snow on top of looser lighter snows up high. Forecast precip models have been reduced slightly this am. With the continued precipitation on top of the weak layer and upside down slab in place AVALANCHE DANGER IS HIGH AT THIS TIME. Please avoid spending time in Avalanche Zones such as the Flume Trail, Perseverance Trail. Please avoid walking or jogging along Thane Road through avalanche paths. Limit your danger by limiting your exposure. Yesterday a portion of Thane Road slid and stopped short of the road. There is additional mass up there today and still areas of weakness. Driving the road yesterday I still saw groups of joggers and walkers heading through avalanche paths. Please recognize you are at risk! This is not a smart place to be during periods of high danger. Douglas Island saw quite a few avalanche yesterday, both natural and man made. Slides were ranging from 30 to 60cm and propagating widely. Running through trees and around terrain features. Cornices are weak and cornice falls have the ability to trigger larger slides. One cornice fall released a nearby slope over a meter deep. A great deal or Woomphing and Cracking was seen in the snowpack during travel. Forecast precipitation rates are predicted to fall. As we go through tonight in to tomorrow temps are also predicted to fall. This weak layer may settle and bond but do not assume anything without doing the research to make good decisions on your own. Time is our friend as this storm cools and precip rates subside we should see some good soft snow on top. But please be aware although backcountry conditions will start to look inviting there is still the presence of a weak layer in places. Please remember when traveling in the backcountry don't leave home without your avalanche transceiver, probe, and shovel as well as a well with a trained partner. ]]>Fri, 11 Feb 2011 00:00:00 -0900http://www.juneau.org/avalanche/index.phphttp://www.juneau.org/avalanche/index.php
The National Weather Service Forecasts- TODAY...BECOMING BREEZY...SNOW. SNOW ACCUMULATION 2 TO 4 INCHES. HIGHS AROUND 28. SOUTH WIND 10 TO 20 MPH INCREASING TO NORTH 25 MPH IN THE AFTERNOON. TONIGHT...PARTLY CLOUDY. WINDY. AREAS OF BLOWING SNOW. SLIGHT CHANCE OF SNOW IN THE EVENING. LOWS 8 TO 18. NORTHEAST WIND 10 TO 20 MPH WITH GUSTS TO 35 MPH IN EXPOSED LOCATIONS. TUESDAY...SUNNY...LOCALLY WINDY. LOCAL AREAS OF BLOWING SNOW. HIGHS AROUND 21. EAST WIND 20 TO 30 MPH WITH GUSTS TO AROUND 50 MPH NEAR DOWNTOWN JUNEAU AND DOUGLAS. OTHERWISE NORTHEAST WIND TO 15 MPH. WIND CHILL TO 25 BELOW. TUESDAY NIGHT...PARTLY CLOUDY. LOCALLY WINDY. LOCAL AREAS OF BLOWING SNOW. LOWS 6 TO 16. EAST WIND 20 TO 30 MPH WITH GUSTS TO AROUND 50 MPH NEAR DOWNTOWN JUNEAU AND DOUGLAS...GUSTS DIMINISHING TO 35 MPH LATE. OTHERWISE NORTHEAST WIND TO 15 MPH. WIND CHILL TO 25 BELOW. We have received fairly consistant snows since 2/8. Since 2/8 we have received 70 cm of new snows including settlement. In the last 24 hours we received 15cm of new snow. Temperatures have fallen by 8c in the last 4 days and continue to fall. Wind loading was minimal during the last part of the storm and considerable during the beginning. Winds have now switched direction and picked up. These winds are directly loading faces on Mt Juneau and Mt Roberts raising current avalanche danger. This wind switch has already caused natural avalanches along Thane road at Snowslide Creek and Cross Bay. Both small slides. This shows us the potential for additional slides along adjacent paths exists and danger continues to build with these direct loading winds and loose snows available for transport. Last week during the first part of the storm we had a fair amount of natural avalanche activity. Thane Road slid at snowslide creek. The White Path Slid. Several other paths slid. Yet many have not and the weakness at the weak layer is still present. There is the possibility of new slabs having developed in the last few days. There is still a weak layer under our 70cm slab as well. Triggers will be fairly easy on the newer surface layers. The greater concern for today is the reactivity of the deeper layers of instability. If we see a small surface slide it could create enough energy to propagate down to the old weak layer in place. Or even the new weight load on a layer that has only moderately settled out may be enough to make that layer reactive once again. Today is a day to know your area, and what slid during our last weeks avalanche cycye. Without that knowledge of what slid previously you could be playing in an area that has far greater potential should it release. Slide sizes are starting to grow to a level of concern especially if we see the deeper weak layers release. Please limit your exposure to avalanche prone areas and use caution and good practices for travel in avalanche terrain. Remember, TRANSCEIVER, PROBE, SHOVEL, and a partner or two trained and equally prepared. Dont head out into the BC without them.]]>Mon, 14 Feb 2011 00:00:00 -0900http://www.juneau.org/avalanche/index.phphttp://www.juneau.org/avalanche/index.php
The National Weather Service Forecasts- TODAY...MOSTLY CLOUDY. FLURRIES IN THE MORNING. LOCALLY VERY WINDY. AREAS OF BLOWING SNOW. TEMPERATURES STEADY IN THE UPPER TEENS. NORTHEAST WIND 10 TO 20 MPH...EXCEPT 20 TO 30 MPH WITH WIND GUSTS AROUND 55 MPH NEAR DOWNTOWN JUNEAU AND DOUGLAS. TONIGHT...DECREASING CLOUDS. LOCALLY WINDY. LOWS 6 TO 16. NORTHEAST WIND 15 TO 25 MPH WITH HIGHER GUSTS NEAR INTERIOR PASSES. WEDNESDAY...PARTLY CLOUDY IN THE MORNING THEN BECOMING SUNNY. BREEZY. HIGHS 17 TO 23. EAST WIND 15 TO 25 MPH WITH HIGHER GUSTS NEAR INTERIOR PASSES. WEDNESDAY NIGHT...MOSTLY CLEAR. LOCALLY BREEZY. LOWS 6 TO 16. SOUTHEAST WIND 15 TO 25 MPH. WIND CHILL TO 20 BELOW. We have received over 10" of light new snow in the last 48 hours at tram summit elevations. Temperatures have fallen by over 15C in the last 36 hours. And much more if you consider wind chill. This places stress on the snowpack by drawing out moisture and exchange of heat transfer. In the last 20 hours we have received over 6" of wind transported snows at our Tram Summit Weather Site. This shows extreme windloading. Winds are predicted to remain high today. The wind direction also directly favors wind slab development in our urban starting zones. Yesterday during the beginning of the wind storm there was enough wind transport to start natural avalanches in many areas along Thane Road such as Snowslide Creek and Cross Bay. Although some of the mass has now been reduced in those areas they can reload do to wind transport in a short period of time. Also in areas that have not seen any silde activity the danger is still present and growing. Yesterday the slabs started out as 8-10" of low density soft slab. As this wind event continues the slab depth can grow do to wind transport of new snows into the starting zones. Also slab densities will build as long as this wind event continues. A greater concern comes in when we consider what this new wind slab is resting on. Ths storm cycle started on February 8th. Temperatures rose by more than 8 degrees during the first part of the storm. This created an upside down snowpack with low density snow under heavier, harder snows on the surface. This creates a weak layer. Since the beginning of the cycle we have received 150mm of precipitation which rests in over 80cm of new snows(over 2 1/2')after settlement. There was quite a bit of natural activity in the first part of the storm removing some of the depth in certain starting zones. But in areas where there was no activity there is now a weak layer present over 2 1/2' deep without even considering the windloading in areas. So if we see the avalanche come in the top storm layers of 10+' and windloading they will be fast avalanches creating a lot of additional stress on the snowpack under them. This has the possibility of then tearing down to the deeper weak layers in place. Recognize that although those deeper layers have had some time to settle and bond the weakness is still present. Should we see avalanche activity down to this deeper weak layer, slide sizes could be quite large. Recognize the factors leading to avalanche are present and danger continues to rise due to windloading. AVALANCHE DANGER IS HIGH AT THIS TIME> Natural avalanches are likely and human triggered avalanches are very likely. ]]>Tue, 15 Feb 2011 00:00:00 -0900http://www.juneau.org/avalanche/index.phphttp://www.juneau.org/avalanche/index.php
The National Weather Service Forecasts- TONIGHT...SNOW...HEAVY AT TIMES. SNOW ACCUMULATION 5 TO 11 INCHES. STORM TOTAL SNOW ACCUMULATION 10 TO 17 INCHES. BREEZY WITH AREAS OF BLOWING SNOW IN THE EVENING. LOWS AROUND 25. SOUTHEAST WIND 15 TO 25 MPH WITH GUSTS TO 35 MPH DIMINISHING IN THE EVENING. SUNDAY...MOSTLY CLOUDY. CHANCE OF SNOW SHOWERS. HIGHS AROUND 33. NORTHWEST WIND 10 TO 15 MPH. SUNDAY NIGHT...MOSTLY CLOUDY WITH SNOW SHOWERS. SNOW ACCUMULATION AROUND 1 INCH. LOWS AROUND 25. NORTHWEST WIND 10 MPH. We have seen 12" of snow in the last 24 hours at tram summit elevations and it continues to stack up at rapid rates. We are expecting as much as a foot or more in the next 12 hours. This is a red flag indicator of high avalanche danger. Winds of 15 to 35 MPH are crossloading our starting zones. Eaglecrest and Douglas Island Winds have been much higher averaging from 25-40 gusting over 50 during this first part of the storm. True summit winds may have been higher along the channel as well but the Mt Roberts Gauge is located only at 1800'. The wind loading at this rate is another red flag indicator of building avalanche conditions. Temperatures have increased by 7 degrees during this first part of the storm and are expected to rise another few degrees during the day tomorrow. This considerable warming trend is not a good thing for avalanche conditions. As this snow continues to stack up at rapid rates accompanied by warming and high winds danger levels are HIGH. Tomorrow will be a great day to head up to Eaglecrest. By later tonight natural avalanches are likely and skier triggered avalanches are very likely. Please avoid places like The Flume and Perseverance Trails as well as walking and jogging along Thane Road. Slide sizes are growing to the size of a concern as we progress through the later part of this snowstorm. Remember the basics of avalanche safety. Simply Avoid Avalanche Terrain During Periods of High Danger. Without an avalanche transceiver, probe, shovel and a partner you have no ability to respond in companion rescue. But by simply avoiding avalanche terrain you can eliminate the need. Be Safe, Make good decisions, and Have a great day! Its NUKIN! ]]>Sat, 19 Feb 2011 00:00:00 -0900http://www.juneau.org/avalanche/index.phphttp://www.juneau.org/avalanche/index.php
The National Weather Service Forecasts- TODAY...INCREASING CLOUDS. HIGHS AROUND 47. LIGHT WINDS. TONIGHT...MOSTLY CLOUDY. ISOLATED RAIN SHOWERS IN THE EVENING. LOWS AROUND 33. LIGHT WINDS. MONDAY...CLOUDY. SLIGHT CHANCE OF RAIN IN THE MORNING. HIGHS AROUND 46. SOUTHEAST WIND 10 MPH. MONDAY NIGHT...CLOUDY. SLIGHT CHANCE OF RAIN. LOWS AROUND 34. SOUTHEAST WIND 10 MPH. It has been above freezing for 4 days straight at tram summit elevations. It has been above freezing for 3 days at Eaglecrest summit elevations. We are loosing the glue that bonds the snowpack together. We are starting to see more free moisture in the snowpack which eats at the current bonds in place. The snowpack also tends to settle rapidly at these above freezing temperatures which also places additional stress on it. We are starting to see a lot of spots of dirt and rock showing up on the hillside. This adds to the thermal stress in the pack by absorbing the heat from the sun. Steep areas around rocks and trees continue to releive themselves. Areas with fewer anchors may becoming more suspect especially at lower elevations. Be aware on steep open faces and when sking above others. Right now durnig it is easy to get a little snow moving and it can pick up quite a bit of mass and momentum. Slide sizes are not expected to be large. But the longer this above freezing temperature persists the greater the danger for deeper weak layers to become reactive. ]]>Sun, 27 Mar 2011 00:00:00 -0800http://www.juneau.org/avalanche/index.phphttp://www.juneau.org/avalanche/index.php
TODAY, RAIN SHOWERS. HIGHS AROUND 46.SOUTHEAST WIND 10/20MPH. TONIGHT,RAIN SHOWERS.LOWS AROUND 36. SOUTHEAST WIND 10/15MPH. THURSDAY, RAIN SHOWERS. HIGHS AROUND 44. SOUTHEAST WIND 10/15 MPH. THURSDAY NIGHT...RAIN SHOWERS. LOWS AROUND 35. SOUTHEAST WIND 10 MPH. We received the first freezing temperatures in 5 days last night at tram summit elevations and higher. We have seen a great deal of above freezing temperatures down low. Much of the lower elevation snowpack is quite moisture saturated at this time and deteriorating rapidly. At upper elevations we received a little new snow last night. This new snow will not bond well and tend to sluff off of trees, rocks, and steep open faces. Be aware these sluffs quite easily become point release avalanches and can entrain quite a bit of mass in longer pitches. Recognizing the lower snowpack has seen a lot of above freezing temperature and is becoming quite rotten, expect to see any point release avalanches coming through these lower elevations cleanout the rotten snow. Although danger is high meaning natural avalanches are likely, larger slides are not predicted. Yet with constant precipitation for the next few days, the ability to trigger deeper weak layers exists. Expect to see activity peak during the warmest part of the day as diurnal fluctuation remains strong with 8-10 degree daily temperature swings. ]]>Wed, 30 Mar 2011 00:00:00 -0800http://www.juneau.org/avalanche/index.phphttp://www.juneau.org/avalanche/index.php
The National Weather Service Forecasts- Tonight...Snow showers...becoming heavy at times by late evening. Snow accumulation 6 to 10 inches. Lows around 28. West wind 10 mph shifting to the east in the evening. Tuesday...Snow showers likely...mainly in the morning. Snow accumulation up to 2 inches. Highs around 32. Southeast wind 10 to 15 mph. Tuesday Night...Snow. Snow accumulation 2 to 6 inches. Lows around 24. Southeast wind 10 to 20 mph. It is still early in the seaon and we do not have mid to late season snow amounts in the starting zones. Avalanche Danger is HIGH at this time due to the heavy precip and accumulation rates. Slide sizes are not expected to be huge yet could be a concern as this new snow continues to stack up. Watch for warming tomorrow to increase danger and natural activity. Give this new snow time to settle and bond. Watch for areas along the FLUME trail. Backcountry danger levels will be high for a few days until this new snow has time to settle and bond. Be safe out there if you even choose to go at all. Time is your friend when you get big snowfall events like this be patient. ]]>Mon, 14 Nov 2011 00:00:00 -0900http://www.juneau.org/avalanche/index.phphttp://www.juneau.org/avalanche/index.php
The National Weather Service Forecasts- TODAY...WINDY. RAIN AND SNOW CHANGING TO ALL RAIN BY THE AFTERNOON. NEW SNOW ACCUMULATION UP TO 2 INCHES. SNOW LEVEL 1400 FEET IN THE AFTERNOON. HIGHS AROUND 37. SOUTHEAST WIND 15 TO 25 MPH WITH GUSTS UP TO 45 MPH DECREASING TO 10 TO 15 MPH IN THE AFTERNOON. TONIGHT...RAIN SHOWERS...THEN NUMEROUS SNOW SHOWERS LATE. SNOW ACCUMULATION UP TO 1 INCH. SNOW LEVEL 1400 FEET DECREASING TO 400 FEET LATE. LOWS AROUND 32. SOUTHEAST WIND 10 TO 15 MPH. TUESDAY...MOSTLY CLOUDY. SCATTERED RAIN SHOWERS AND SNOW SHOWERS. HIGHS AROUND 39. SOUTH WIND 10 MPH. We have quite a bit of loose unconsolidated snow on the ground. Ranging from about 165cm at tram summit levels to about 250cm at local summit elevations. There is not much in the way of crust in the layering. The Mt Roberts Tram weather station shows we have received about 22mm of precipitation in the last 12 hours this came in the form of about 18cm of new snows. This is some of the wettest heaviest snow we have seen in a while on top of quite a bit of looser lighter snows that were in place... A loading rate of 25mm of precip per day is a red flag indicator of building avalanche conditions. You can see we have reached almost that in less than 12 hours. Winds went from almost zero to 30+ knot averages over the last 12 hours as well... This too is a red flag indicator of building avalanche conditions. Temperatures have risen 4+ degrees in the last 24 hours and are expected to continue to rise today up through the freezing point to 1400'... Temperatures rising during heavy precip and winds are also a red flag indicator of building avalanche conditions. Temperatures today will be the warmest we have seen in over a week during which time we have received over 50cm(2feet) of new snows after settlement and consolidation. With 3 out of 3 weather readings giving us red flag indicators of building avalanche conditions, Avalanche Danger is HIGH at this time... Potentially destructive natural avalanches likely to come near or reach developed areas, natural and human triggered avalanches likely. Todays precipitation loading rates are not high to extreme(we expect about .31" of moisture)... but with added windloading to an upside down pack... this is still a concern... There has not been much in the way of active avalanche activity in the last few weeks. There are not many pronounced base and slide layers in the pack. So although we are rapidly building concerning avalanche conditions... there is not currently an active layer they are running on... This warm weather, loading, and precip will create a tremendous amount of settlement and stress on the snowpack. The only question that remains is will this pack settle in place... or in the vertical motion in the form of an avalanche. Today is a good day to avoid the backcountry, the flume trail, and any other avalanche zones in the community.]]>Mon, 28 Nov 2011 00:00:00 -0900http://www.juneau.org/avalanche/index.phphttp://www.juneau.org/avalanche/index.php
The National Weather Service Forecasts- TODAY...WINDY. RAIN. SNOW LEVEL 1400 FEET IN THE MORNING. HIGHS AROUND 42. SOUTHEAST WIND 15 TO 25 MPH WITH GUSTS TO 45 MPH...WINDS DIMINISHING IN THE LATE AFTERNOON. TONIGHT...BECOMING WINDY AGAIN. RAIN. LOWS AROUND 37. SOUTHEAST WIND 15 MPH INCREASING TO 25 MPH WITH GUSTS TO AROUND 40 MPH IN THE LATE EVENING. FRIDAY...WINDY...RAIN. SNOW LEVEL LOWERING TO 300 FEET IN THE AFTERNOON. HIGHS AROUND 38. SOUTHEAST WIND 30 MPH WITH GUSTS TO AROUND 40 MPH DECREASING TO 10 TO 20 MPH IN THE AFTERNOON. Although the forecasted freezing level states 1400 for this am it appears to be over 1800 already. The Mt Roberts Tram Wx Station shows +2C temps while the Eaglecrest summit gauge is showing about -1/2c. Eaglecrest UAS weather station shows having received 11" of new snow in the last 24 hours. Temperatures came up by 4 degrees during that time and are now hovering at 0. The Mt Roberts Wx station is showing 40mm of precipitation in the last 24 hours and the gauge quit working at 2am so it is probably much more... This gave us 28cm of snow by 2am. But then my gauge quit working... Most of the precip after this time came down as rain at this elevation. Which is rapidly destabilizing the snowpack. Winds ranged from 20 to 60 knots out of the SSE during this event. Highest winds were on Douglas Island. With another 1" of precip possible in the forecast, winds from 20-30 knots and gusting to 45, Over a foot of new snow on the ground at upper elevations with lots of windloading... AVALANCHE DANGER IS HIGH AT THIS TIME. Potentially destructive natural avalanches likely to come near or reach developed areas, natural and human triggered avalanches likely. I would hope the lower deep layers will continue to hold strong bonds. Yesterday showed some weakness at the old snow surface from the rains a few weeks back on the Mt Roberts faces. These are the warmest temps we have seen since this rain event two weeks ago. This new load will continue to test the snowpack down to this old rain crust interface. We are dealing with an upside down snowfall event that had rapid snowloading, windloading, and has now warmed through freezing at lower elevations. Many red flags are present. As temps start to cool off late tonight and into tomorrow the snowpack should start to stabilize again. Today is a great day to use extra caution. ]]>Thu, 22 Dec 2011 00:00:00 -0900http://www.juneau.org/avalanche/index.phphttp://www.juneau.org/avalanche/index.php
The National Weather Service Forecasts- TODAY...SNOW IN THE MORNING...THEN RAIN IN THE AFTERNOON. SNOW ACCUMULATION UP TO 2 INCHES. SNOW LEVEL RISING TO 600 FEET. HIGHS AROUND 36. SOUTHEAST WIND 15 TO 25 MPH. GUSTS TO 35 MPH IN THE MORNING. TONIGHT...RAIN...CHANGING TO SNOW IN THE EVENING. SNOW ACCUMULATION 2 TO 5 INCHES. SNOW LEVEL 600 FEET IN THE EARLY EVENING. LOWS AROUND 30. SOUTHEAST WIND 10 TO 15 MPH. THURSDAY...RAIN AND SNOW. SNOW ACCUMULATION 1 TO 2 INCHES. HIGHS AROUND 35. SOUTHEAST WIND 10 TO 20 MPH. We have received 1.2" of precipitation and 10+" of new snow over the last 18 hours while the winds blew from 20-50 knots out of the SSE. Lets keep it simple folks... AVALANCHE DANGER IS HIGH AT THIS TIME!!! Potentially destructive natural avalanches likely to come near or reach developed areas, natural and human triggered avalanches likely. Todays forecast calls for a touch more warming, continued winds, and several inches of new snow. Dangers may decrease ever so slightly through the day today but will increase again tonight into tomorrow with increased precipitation rates at that time. One of the bigger problems is that all this new snow is being windloaded into our starting zones and is coming to rest on an ice layer that it will not bond well to the new snow for some time. Densities started quite low early in the cycle yet have greatly increased. Overall densities are over 12% at this time. This is an upside down snowpack folks. Placing heavy wet snow on looser lighter snow... You have a stack of bricks sitting on a pop can once again... It may be holding for now... but if you step on the brick... that pop can is going to colapse... And this brick pile on the pop can is resting on an ice skating rink... How is that for some hi tech avalanche info.. The new precipitation rate for today has decreased slightly which may keep us out of a large natural avalanche cycle... Yet some natural avalanches may have already occured and there may still be more. But if your heading out into the mountains be aware... The mouse trap has been set... and is waiting for you to step in the wrong place... DONT GET CAUGHT! Today is a great day to avoid places like the Flume and Perseverance Trail! Danger is also quite high along Thane road... as the berm is very full and the avalanche track has been filled in and greased by all the other recent avalanche activity... The Urban paths have a little less danger as there is a little more runout between the bottom of the track and the houses... But danger still exists as it is hard to precisely predict how far these avalanches could run. There are 5 red flag indicators of HIGH avalanche danger... Today all 5 are present. Most of the activity should be limited to this 10+" of new snow. Yet be aware in windloaded areas there may be much more depth in the slab adding to the avalanche size. If you do head out into the mountains today stick to low angle, well anchored slopes, no terrain traps, no exposure to cliffs, rocks, etc... For that matter... It may simply be a good day to wait it out... give the snowpack time to settle and bond. Tomorrow AM Eaglecrest will be doing avalanche control and the lift skiing will be safe and AWESOME!!! Have a great day.]]>Wed, 11 Jan 2012 00:00:00 -0900http://www.juneau.org/avalanche/index.phphttp://www.juneau.org/avalanche/index.php
The National Weather Service Forecasts- TODAY...RAIN. SNOW LEVEL 900 FEET. HIGHS AROUND 38. SOUTHEAST WIND 15 TO 25 MPH. GUSTS TO 35 MPH IN THE MORNING. TONIGHT...RAIN SHOWERS AND SNOW SHOWERS. SNOW ACCUMULATION UP TO 2 INCHES. SNOW LEVEL 500 FEET IN THE EVENING. LOWS AROUND 32. SOUTHEAST WIND 10 TO 15 MPH. FRIDAY, SNOW SHOWERS DIMINISHING IN THE AFTERNOON. SNOW ACCUMULATION 1 TO 3 INCHES. HIGHS AROUND 31 EARLY. TEMPERATURES FALLING THROUGH THE DAY. SOUTHEAST WIND 10 TO 15 MPH. Over the last 40 hours we have seen quite a good storm front move through. Precipitation totals have continually been higher than the forecast amounts. Winds have been quite high. We have received 70mm (2.8") of precipitation at the Mt Roberts Tram Summit in the last 40 hours. 40mm(1.6")of that came in the last 24 hours. Where the UAS gauge is reading 30cm (1') of new snow after taking into account overall snowpack settlement and consolidation, the tram summit gauge is showing closer to 45cm (18"). This shows us that spatial variability is quite high and densities are likely quite high as well. This is during a time that the temperatures rose by 8+ degrees at the Mt Roberts Tram Summit and 10+ degrees at the Eaglecrest Summit. The majority of this warming came in the first 16 hours but Eaglecrest Summit temps rose by 3 degrees in the last 24 hours and the tram summit rose by about the same right up to 32f at one point. Temperatures have cooled by about 1 degree in the last few hours. But are still very close to freezing at both the Tram Summit and the UAS Mid Mountain Gauge at Eaglecrest. Winds over the last 40 hours have been quite high as well. Starting off blowing out of the SSE at 25-70mph then slowing a little bit in the last 15 hours to 20-45mph which still generates considerable windloading. Spatial Variability is quite high as I mentioned. This new snow came in on top of a relatively hard icy surface in most places which we would typically equate to quite poor bonding. This new snow also came in through great warming which we would typically equate to a very upside down snowpack. But winds were quite high in this storm front from the very beginning. This tends to break down the snowflakes and make them much smaller right from the first minute which can help them to pack to much higher densities than a typical no wind snowpack would see. Where we expected to see a great weakness in the snowpack yesterday and natural avalanche activity I was suprised to actually see very little weakness in the snowpack and almost no natural avalanche activity. Over the last 24 hours we saw a majority of our moisture and for a 40 hour period accumulations totals were very high with considerable to high winds. Even considering the lack of weakness and activity yesterday with the overall conditions in place it is quite difficult for me to say avalanche danger is less than HIGH today. With an additional 1" of precipitation in the forecast models for the next 24 hours avalanche danger will remain HIGH today. Potentially destructive natural avalanches likely to come near or reach developed areas, natural and human triggered avalanches likely. It appears the majority of the precipition is heading south today. By mid day tomorrow we should start drying out and cooling off. Avalanche danger will start to fall at that time. Today is a great day to avoid places like the Flume and Perseverance trail. Remember that the berm on Thane Road is also quite full and it will not take much of an avalanche with these high volumes of snow to reach the road. Time is your friend. The more time we give this new snow to settle and bond the stronger it will become. Have a great day and be safe. ]]>Thu, 12 Jan 2012 00:00:00 -0900http://www.juneau.org/avalanche/index.phphttp://www.juneau.org/avalanche/index.php
The National Weather Service Forecasts- TODAY...SNOW. SNOW ACCUMULATION 2 TO 4 INCHES. HIGHS AROUND 33. EAST WIND 10 TO 20 MPH. TONIGHT...SNOW. SNOW ACCUMULATION 4 TO 8 INCHES. LOWS AROUND 31. EAST WIND TO 15 MPH. WEDNESDAY...SNOW IN THE MORNING...THEN SNOW AND RAIN SHOWERS LIKELY IN THE AFTERNOON. SNOW ACCUMULATION AROUND 4 INCHES. STORM TOTAL SNOW ACCUMULATION 8 TO 12 INCHES. HIGHS AROUND 35. NORTH WIND 10 MPH SHIFTING TO THE SOUTH IN THE AFTERNOON. We received 28cm (11") at the Mt Roberts Tram Wx station in the last 24 hours and about 20mm or precipitation.. Roughly 7% pow... The Eaglecrest UAS site is only showing around 20cm (8") during that same time. Winds were considerable from 15-35mph out of the SSE then shifting to the East early this AM. Look to see considerable windloading on the N-W aspects today. Temperatures have remained fairly constant. With as much as 17" of additional snow in the forecast for the next 24 hours in our mountain regions and continued winds avalanche DANGER IS HIGH at this time. The likeliness of natural avalanche will build more over time as this new snow starts to accumulate to higher volumes especially tonight into tomorrow. Potentially destructive natural avalanches likely to come near or reach developed areas, natural avalanches are likely especially as we start to see greater accumulations. Human triggered avalanches very likely. Early on today we may not see much in the way of natural avalanches but conditions will continue to build. If we should happen to see natural releases of our 4 day possible storm total by the end of this event the slabs could be as great as 33" (16" in last 72 hours plus another 17" possible in the next 24) in depth plus whatever windloading may have occured. Odds are good that the first 8" will remain in place so the slides may not be quite as large. But once they get rolling there is the potential to strip down to the lower weak layers in place in certain spots. Danger on Thane road is HIGH today. It is a great day to limit or avoid travel in that cooridor. Especially tonight into tomorrow as we start to see greater new snow accumulations. Also be aware that the Flume and Perseverance Trails will have great danger for the next 24-48 hours. Today in the urban enviroment slides are not predicted to occur right away or expected to be large. Yet once again from tonight into tomorrow these slide sizes will be increasing and we will have greater danger. The best way to limit your avalanche danger is to simply limit your exposure by avoiding avalanche prone areas. Temperatures will rise slightly tomorrow and we predict that by mid day tomorrow danger levels will have peaked. After the mid day diurnal fluctuation in temperatures we expect to see some gradual cooling and reduction in the precipitation rates. Hopefully danger will start to decrease at that time. Have a great day, Drive Safe, and be EXTREMELY cautious in the mountains should you choose to venture out. Remember good safety practices, spotters watching partners from islands of safety to islands of safety, Always carrying your avalanche transceiver, probe, and shovels. Consider staying to lower angle slopes, more trees, and less exposure especially to terrain traps. ]]>Tue, 24 Jan 2012 00:00:00 -0900http://www.juneau.org/avalanche/index.phphttp://www.juneau.org/avalanche/index.php
The National Weather Service Forecasts- TODAY,SNOW DIMINISHING IN THE LATE MORNING. SNOW ACCUMULATION 5 TO 8 INCHES. STORM TOTAL SNOW ACCUMULATION OF 6 TO 11 INCHES. WITH LOCALLY HIGHER AMOUNTS. HIGHS AROUND 36. SOUTH WIND 10 TO 20 MPH. TONIGHT...SNOW SHOWERS. SNOW ACCUMULATION 1 TO 4 INCHES. LOWS AROUND 28. SOUTH WIND 10 TO 20 MPH. THURSDAY...SNOW LIKELY. SNOW ACCUMULATION 1 TO 2 INCHES. HIGHS AROUND 31. SOUTHEAST WIND 10 TO 15 MPH. On Sunday we received approx. 7" of new snow in our mountain starting zones. This came in fairly dense and is bonding fairly well in places. From Monday into Tuesday we received about 20m of precip that left about 28cm (10-11")of approx 7% snow (light and dry). From last night into today we received another 26mm of precip that left about 20cm (8") of approx. 13% new snow (wetter and heavier). Temperatures rose all day yesterday by about 7 degrees right to the point of freezing at tram summit elevations and peaked out last night by about midnight. Since that time they have cooled off slightly allowing the densities to fall again slightly for this mornings new snow. So we placed a 10+" layer of pop cans down (low density), then we covered it up with about an 8" thick cinder block (higher density). Now we are finishing it off with another few inches of bricks (new moderate density snow). It is only a matter of time until the pop cans colapse. The lower layers are slowly getting stronger over time and the brick layer is tiring out (our precipitation rate is decreasing). So we hope the brick layer tires before the pop cans get crushed!!! (creating an avalanche). Should these avalanches occur there is a possibility they could tear down into the deeper layers of the snowpack. Since Saturday night that could be as much as 26" of snow plus windloading in places. In a worst case scenario this could even tear down deeper in the snowpack in places due to deeper layers of instability that have been left behind since about Jan 8th. We do not expect to see the worst case scenario yet with enough stress on the snowpack this too is possible. Winds were fairly calm during the first part of the week but have picked up in the last 24 hours to as much as 35 mph adding windloading and additional stress to the equasion. The direction changed several times rolling from the SE all the way to SW... So you can assume anything but a North facing slope will have some degree of windloading. With several inches of new snow in the forecast for this morning accompanied by several degrees of warming and continued moderate winds, avalanche danger is HIGH at this time. Potentially destructive natural avalanches likely to come near or reach developed areas, natural avalanches are likely and human triggered avalanches are very likely. If we get through the mid day warming and new snow in the forecast without natural avalanches danger levels may decrease slightly this evening as the cooling occurs and the snowpack has time to settle and bond. But human triggered avalanches will remain likely for a while longer. Also later tonight we expect to see additional precipitation enter our region again. So we do not expect to see danger levels decrease in the next 24 hours overall. Danger on Thane road is HIGH today. It is a great day to limit or avoid travel in that cooridor. Also be aware that the Flume and Perseverance Trails will have great danger for the next 24-48 hours. There is high danger in the urban zones as well today both in the Berhands and White path zones. Especially if the deeper weak layers become reactive once again. The best way to limit your avalanche danger is to simply limit your exposure by avoiding avalanche prone areas. Today is a great day to exercise additional caution in all areas. ]]>Wed, 25 Jan 2012 00:00:00 -0900http://www.juneau.org/avalanche/index.phphttp://www.juneau.org/avalanche/index.php
The National Weather Service Forecasts- TONIGHT...SNOW SHOWERS. SNOW ACCUMULATION 2 TO 5 INCHES. LOWS AROUND 25. EAST WIND 10 TO 20 MPH WITH HIGHER GUSTS. FRIDAY...SNOW SHOWERS. SNOW ACCUMULATION 1 TO 3 INCHES. HIGHS AROUND 30. SOUTHEAST WIND 10 TO 15 MPH. FRIDAY NIGHT...NUMEROUS SNOW SHOWERS. SNOW ACCUMULATION 1 TO 2 INCHES. LOWS AROUND 27. SOUTHEAST WIND 10 TO 15 MPH. We are seeing 25+ knot winds currently out of the East. We have a lot of loose snow on the hill today. This is directly loading the urban starting zones. Winds load slopes faster than new snow can from falling and tends to build weak layers and slabs. We will also be seeing several inches on new snow overnight adding to the equasion with building stress in the snowpack. Todays field results showed weak layers in the snowpack that were being skier triggered which shows they are close to natural failure which can lead to avalanches. Temperatures are expected to remain cool. Winds will be considerable overnight and will continue to load our urban paths. The lower deep layers in the snowpack have started to settle some and bond yet there are still many weak layers present at different depths. Should avalanches occur they have the potential to tear down to the deeper weak layers in place. Avalanche danger is HIGH overnight tonight with the direct windloading on top of the current weak layers. Tonight is a great time to avoid travel in the urban avalanche zones especially along Thane Road, The Flume and Perseverance Trails. The Berhands and White path avalanche zones are also extremely loaded with snow right now and this wind event could start dry slab avalanches which travel quite fast and have the ability to cause damage even from the wind blast that procedes them and also travels farther then the avalanche itself. This forecast will be updated before 7am tomorrow. Potentially destructive natural avalanches likely to come near or reach developed areas. Natural and human triggered avalanches likely, especially if we see more snow than originally forecast or greater loading winds. Here is a little info for you from the storm system that built the deeper weak layers currently in place over the last few days. On Sunday we received approx. 7" of new snow in our mountain starting zones. This came in fairly dense and is bonding well in most places. From Monday into Tuesday we received about 20m of precip that left about 28cm (10-11")of approx 7% snow (light and dry). From Tuesday evening into Wednesday we received another 26mm of precip that left about 20cm (8") of approx. 13% new snow (wetter and heavier). Temperatures rose all day Tuesday by about 7 degrees right to the point of freezing at tram summit elevations and peaked out by about midnight. Wednesday AM until now they have cooled off by 7C degrees and we have seen several inches of new snow on top of the lower weak layers. So we placed a 10+" layer of pop cans down (low density), then we covered it up with about an 8" thick cinder block (higher density). Now we are finishing it off with another several inches of moderate density snow and loading winds. It is only a matter of time until the pop cans colapse. Hopefully winds will die off or shift direction and new snow loading will be at a minimum. Aviod spending time in the urban avalanche zones.]]>Thu, 26 Jan 2012 00:00:00 -0900http://www.juneau.org/avalanche/index.phphttp://www.juneau.org/avalanche/index.php
The National Weather Service Forecasts- TONIGHT...SNOW BECOMING MIXED WITH RAIN BY LATE EVENING. SNOW ACCUMULATION 2 TO 3 INCHES. TEMPERATURES RISING TO AROUND 35 BY LATE TONIGHT. SOUTHEAST WIND 10 TO 15 MPH. TUESDAY...RAIN. SNOW LEVEL 1200 FEET. HIGHS AROUND 36. SOUTHEAST WIND 10 TO 15 MPH. TUESDAY NIGHT...RAIN. SNOW LEVEL 700 FEET. LOWS AROUND 33. LIGHT WINDS BECOMING SOUTH 10 MPH LATE. We had light winds most of the day yesterday from 5-10mph out of the SE. We had slight warming yesterday morning before the new snow came in. Temperatures cooled slightly during the majority of the snowfall yesterday. From Midnight on Saturday until 5pm today we have received 27mm of precipitation at the Mt Roberts Tram Summit Weather Station. This showed 17cm of new snow on the overall snowdepth sensor. This number does not take into account overall snowpack settlement and consolidation so you can assume the 24 hours snowfall was much greater and getting denser. This is moderate to considerable loading. Last night around 9pm winds picked up to 10-15mph. Later around 2am they again rose from 10-20mph. Now they are over 30mph. During this time they slowly shifted from the NW around to the SSE. This created moderate windloading on the slopes facing SE around to NNW. Temperatures have risen by 4-5+ degrees in the last 24 hours. With additional warming overnight tonight and freezing levels going to 1200 feet by morning, continued precipitation with snow down low turning to rain, and continued moderate to considerable winds at summit elevations out of the SE, avalanche danger is HIGH at this time. Natural avalanches likely especially down low and in the steep filled in paths in the urban enviroment along Thane Road, The Flume and Perseverance Trail. Even possibly the Berhands and White Paths. With massive snowloads in place, the glide track filled in and warming temps it wont take much additional moisture overnight into tomorrow morning to get things moving in places. With the deeper weak layers in place and lots of unconsolidated snow surface avalanches have the ability to step down deeper into the snowpack. Should this occur, potentially destructive avalanches may come near or reach developed areas. Human triggered avalanches likely, especially on steep open faces, unsupported slopes, on any convexity or in windloaded areas. Todays fieldwork showed easy skier triggers with slabs over 2' propagating widely in places. Overnight precipitation rates will increase. The forecast calls for as much as 1" of precip in the next 24 hours with continued warming into tomorrow morning. As we see continued warming overnight into tomorrow with rising freezing levels and additional precipitation avalanche danger is HIGH. To avoid avalanche danger simply avoid avalanche terrain. Tonight and even more so tomorrow are a great time to limit your exposure to these avalanche prone areas. Be safe and have a great day.]]>Mon, 30 Jan 2012 00:00:00 -0900http://www.juneau.org/avalanche/index.phphttp://www.juneau.org/avalanche/index.php
The National Weather Service Forecasts- TODAY...RAIN. SNOW LEVEL 1000 FEET. HIGHS AROUND 38. SOUTHEAST WIND 10 TO 15 MPH. TONIGHT...RAIN. SNOW LEVEL 800 FEET DECREASING TO 400 FEET LATE. LOWS AROUND 33. SOUTHEAST WIND 10 MPH. WEDNESDAY...CLOUDY. CHANCE OF RAIN. HIGHS AROUND 38. SOUTHEAST WIND 10 TO 15 MPH. In the last 36 hours temperatures have risen by 8-10f degrees at Eaglecrest Summit and the Mt Roberst Tram Summit respectively. Winds were from 10-20mph Sunday night into Monday afternoon out of the SSE and picked up last night around 4pm to 20-40mph out of the South. We have received 37mm of precip overall since Sunday morning. 20MM of that coming through the day on Sunday then another 17mm of that in the last 24 hours. We received the last 10mm (.4") of precip in the last 12 hours during the warmest part of our storm which was also accompanied by those high winds. We are creating an upside down snowpack placing high density and wind driven snow on top of the looser lighter snows that were in place on Sunday. With slight additional warming in the forecast for today and another .55" of precip in the forecast for the next 24 hours at these warmer temperatures avalanche danger is HIGH at this time. Potentially destructive natural avalanches likely to come near or reach developed areas,especially along Thane Road. We may also see natural avalanche activity in the White Path, as well as perhaps along the Flume and Perseverance Trail. The Berhands path is also a concern. Thane Road will be closed from 10am to Noon as the DOT performs avalanche control. This will give us a better indication of the size and volume of avalanche potential should any other natural avalanches occur. THANK YOU DOT! Natural and human triggered avalanches likely. Yesterdays field work showed that skier triggered avalanches were easy to create and with this additional windloading, warming, and continued precipitation throughout the day today this danger is continuing to increase. As we start to dry out a little this afternoon and temperatures start to cool a little tonight danger will decrease slightly for a while. After 3pm tomorrow afternoon into Thursday the forecast calls for continued warm temperatures once again with over 1" of precip in the forecast from Wed-Thurs... and again from Thursday into Friday... Avalanche danger will be high once again during that time. Today is a great day to limit your exposure to avalanches by simply avoiding avalanche terrain. ]]>Tue, 31 Jan 2012 00:00:00 -0900http://www.juneau.org/avalanche/index.phphttp://www.juneau.org/avalanche/index.php
The National Weather Service Forecasts- STRONG WIND FROM THIS AFTERNOON THROUGH THIS EVENING... REST OF TODAY...MOSTLY CLOUDY...BECOMING WINDY. SCATTERED RAIN SHOWERS...MIXED WITH SNOW AT TIMES. HIGHS AROUND 39. SOUTHEAST WIND 10 TO 15 MPH INCREASING TO 15 TO 25 MPH WITH GUSTS TO 40 MPH IN THE AFTERNOON. TONIGHT...WINDY...RAIN. SNOW LEVEL 900 FEET LATE. LOWS AROUND 35. SOUTHEAST WIND 20 TO 30 MPH WITH GUSTS TO AROUND 40 MPH DIMINISHING LATE. THURSDAY...RAIN. SNOW LEVEL 1200 FEET IN THE MORNING. HIGHS AROUND 40. SOUTHEAST WIND 15 MPH. Natural Avalanches sited around the community. Avalanche danger continues to rise. Avalanche Forcaste will be updated again within two hours, by approximatly 6:30pm. Monday night into yesterday morning as freezing levels rose accompanied by rains we went into a small natural avalanche cycle. Natural avalanches were sighted on Thane Road and in several paths above the Flume and Perseverance Trails. DOT Avalanche Mitigation work above Thane Road yeilded 4 notable avalanches even after the first natural event of the morning. They pulled down 2 avalanches in Snowslide Creek. One stopping short of the berm and the other reaching the berm with little or no volume. The other two avalanches were in the Cross Bay path. One down the center of the bowl that came about 500' below the center bench stopping well above the road and the other off of the far lookers right near the cornice line area stopping on the bench itself. There may have been additional small releases right in the starting zones but those were not visible above the cloud layer. This helped to remove a great deal of volume from the starting zones in most places and also showed us that while avalanches were easy to trigger they were not massive or running super fast or super far over the lower mountain rain wetted snow. Thank you DOT for doing this before the next few days storm. Temperatures have cooled by 1c degree over the last 24 hours. Winds have calmed down as well, now ranging from 5-15mph. We received 27mm of precip in the last 48 hours but only 10mm of that in the last 24. This rain and warmer temperature helped the lower snowpack to settle greatly as well as reducing some of the volume in the avalanche paths. Now with the cooler temperatures in place this morning things are a little more stable. At upper mountain elevations we still received additional snows that were all quite heavy and wind driven. This can add to the present instability at upper elevations. Especially in windloaded pockets. With the slightly cooler temperatures this morning and not much precip in the forecast for the next 8 hours avalanche danger is Moderate to Considerable at this time. Natural avalanches remain possible especially below the freezing line yet are not as likely. Human triggered avalanches are still probable especially at upper elevations and on steep open unsupported faces, windloaded areas or convex rolls. After 3pm this afternoon precipitation rates will increase greatly. We expect to see as much as 1.25" of precip from 3pm today into 3pm tomorrow. Temperatures will cool slightly overnight tonight then increase to 40+ tomorrow throughout the day. From 3pm tomorrow into 3pm on Friday the forecast calls for as much as 2.08" of precipitation with no cooling over this time. Temperatures will remain near 40 overnight tomorrow night. Once this storm hits today expect to see danger levels rise continually. Now danger is Moderate to Considerable. It will go to considerable overnight tonight. From tomorrow through Mid Day on Friday I expect avalanche danger to be high once again. The size of the avalanches will be determined by how much snow we see up high before this additional warming, as well as by how much rain we actually see and what the intensity rate is. This has the ability to affect lower weak layers in the snowpack that have not seen stress for quite some time. By mid day Friday we expect to see things drying out and starting to cool back off. Avalanche danger is expected to slowly fall after that time. The next 48-60 hours are a great time to exercise extreme caution in avalanche prone areas. Be safe out there folks! ]]>Wed, 01 Feb 2012 00:00:00 -0900http://www.juneau.org/avalanche/index.phphttp://www.juneau.org/avalanche/index.php
The Natural Weather Service Forecasts- TONIGHT...WINDY...RAIN. SNOW LEVEL 900 FEET. LOWS AROUND 35. SOUTHEAST WIND 20 TO 30 MPH WITH GUSTS TO AROUND 40 MPH. THURSDAY...RAIN. HIGHS AROUND 41. SOUTHEAST WIND 10 MPH. THURSDAY NIGHT...RAIN IN THE EVENING...THEN CHANCE OF RAIN LATE. LOWS AROUND 37. SOUTHEAST WIND 10 TO 20 MPH INCREASING TO 25 MPH LATE. FRIDAY...RAIN. HIGHS AROUND 40. SOUTHEAST WIND 15 TO 25 MPH WITH GUSTS TO AROUND 40 MPH. From midnight on the 30th until 2pm today we received approx 20mm(.8) of new snow. This could have been nearly 8" of new snow at our local summit elevations. During that time we had considerable winds out of the SSE. We had several weak layers in place previous to this event and had been slowly building towards a natural avalanche cycle by placing this very heavy snow on the previous soft snows in place. Mid-day today from 2-4:30 we had a breif spike in temperatures from 31-33.5F at Tram Summit elevations. During that time we had 6mm of precip and roughly 6cm of new snow with 40-60mph winds out of the SSE. The combination of these events was enough to lead us into a direct action avalanche cycle. The snowpack had reached maximum load capacity and the direct affect of the new snow, warming, and wind kicked off a natural avalanche cycle. Avalanches were sighted on multiple aspects throughout the Juneau region. In this period of 2+ hours I received calls about a number of natural avalanches. The Bathe Creek Avalanche path was reported to have slid. Several other paths were also reported to have slid on several aspects of Mt Roberts. Towards the end of this event the Berhands path slid. Although this avalanche probably started as a dry slab avalanche near the summit elevations it quickly turned into a wet avalanche at lower elevations. This slowed the slide considerably and it then started to follow the terrain. The transverse gulley at the bottom of the avalanche path which had a fair amount of snow in it still caught most of the slide and directed it towards the south. This natural avalanche stopped below Judy Avenue and above Troy Avenue. It stayed North of the closed road gates and did not affect the urban residents in the avalanche path. As it was near dark I was not able to see how much of the starting zone released. If not all of the starting zone released there is still natural avalanche potential in this path. Please do not go up into the area to look or to walk your dogs above the close road gates. It is still questionably unsafe in that area. There are still several other avalanche paths in the urban enviroment that have not slid and the potential remains. We are still seeing new snows at summit elevations tonight. We expect as much as another .54" of precip by 9am tomorrow which could deliver another 5-6" of wet heavy snow at summit elevations. Adding once again to the danger. We expect as much as another 1.18" of precip in the next 24 hours. This is critical loading and places tremendous stress on the large already weak layers in place. From 3pm to 9pm tomorrow during the warmest portion of this storm and at the warmest temperatures we have seen in quite some time we expect to see as much as another .5" of precip. This is also placing tremendous stress on the snowpack once again. The 48 hour outlook calls for as much as another 2.07" of precip. Also at critical loading levels accompanied by winds and very warm temperatures. Avalanche danger is HIGH at this time and will remain HIGH for the next 48 hours. Even though some paths have shed. They will continue loading overnight. And with multiple weak layers in place there is potential for avalanches to release at deeper depths than we have seen previously. Size during this type of an event is hard to predict but it is fair to say they will not be small... Danger will remain high and avalanche sizes will vary from path to path. Do your best to avoid travel in avalanche prone areas for the next 48 hours. Limit your time along places such as Thane Road, The Flume and Perseverance Trail. Recognize the White Path has not slid yet nor have the other urban paths from the Berhands Path all the way over to the White Path just North of Wickersham Ave. Backcountry danger is also quite HIGH! Potentially destructive natural avalanches likely to come near or reach developed areas, natural and human triggered avalanches likely.]]>Wed, 01 Feb 2012 00:00:00 -0900http://www.juneau.org/avalanche/index.phphttp://www.juneau.org/avalanche/index.php
The National Weather Service Forecasts- TODAY...RAIN. HIGHS AROUND 41...TEMPERATURES FALLING IN THE AFTERNOON. SOUTHEAST WIND 15 TO 20 MPH WITH GUSTS TO 35 MPH DIMINISHING TO EAST 10 MPH IN THE AFTERNOON. TONIGHT...RAIN...HEAVY AT TIMES. BECOMING VERY WINDY. LOWS AROUND 34 RISING TO NEAR 40 LATE. NORTHEAST WIND 10 MPH BECOMING SOUTHEAST 25 TO 35 MPH WITH GUSTS TO AROUND 55 MPH LATE. FRIDAY...VERY WINDY. RAIN. HIGHS AROUND 44. SOUTHEAST WIND 0 TO 30 MPH WITH GUSTS TO AROUND 60 MPH...POSSIBLE. Thane Road slid and buried the road just after midnight last night. DOT Crews will be playing cleanup this morning. My understanding is they like to do avalanche control once again before placing crews in the slide path. I do not forsee the road being open before noon but this is a DOT question... Just wanted everyone to know AVALANCHES ARE STILL OCCURING. From 4pm yesterday until Midnight we had just barely negative temperatures, 30-60mph winds, 18mm of precip at the Tram Summit Weather Station, and about 13cm of new snow. You can expect there to be more snow at higher elevations adding to the stress and mass equasions. From after midnight until 6:30am temperatures rose from 31f to 34f at the tram summit. Winds have slowed to 20-40MPH out of the SSE. We expect to see slightly cooling temperatures through this morning with only .21" of precip through the 3pm hour. After 3pm today through 3 pm tomorrow we expect to see temperatures rising by 5degrees to the warmest temperatures we have seen in well over a month, maybe more. During this time we expect large amounts of rain coming out of this tropical fetch. From 3pm to 3am tonight expect as much as an additional 1.05" of precip, then from 3am Friday until 3pm Friday we expect as much as another .8". Bringing our 24 hour totals to 1.85" which will place tremendous stress on the snowpack especially at the warmest temps we have seen in quite some time. With the warmest temps we have seen in months, and the largest volumes of moisture we have seen all season... Avalanche Danger will remain HIGH. Lower weak layers in the snowpack that were previously dormant will become suspect once again. So even though we have now had several avalanches in some of our larger urban avalanche paths that is not to say we couldnt see another round of slides at perhaps even greater sizes?? STAY OUT OF AVALANCHE PRONE AREAS FOR THE NEXT 36-48 HOURS! Here is a little more back data for you that I wrote last night around 8pm. From midnight on the 30th until 2pm on the 1st we received approx 20mm(.8) of new snow. This could have been nearly 8" of new snow at our local summit elevations. During that time we had considerable winds out of the SSE. We had several weak layers in place previous to this event and had been slowly building towards a natural avalanche cycle by placing this very heavy snow on the previous soft snows in place. Mid-day on the 1st from 2-4:30 we had a breif spike in temperatures from 31-33.5F at Tram Summit elevations. During that time we had 6mm of precip and roughly 6cm of new snow with 40-60mph winds out of the SSE. The combination of these events was enough to lead us into a direct action avalanche cycle. The snowpack had reached maximum load capacity and the direct affect of the new snow, warming, and wind kicked off a natural avalanche cycle. Avalanches were sighted on multiple aspects throughout the Juneau region. In this period of 2+ hours I received calls about a number of natural avalanches. The Bathe Creek Avalanche path was reported to have slid. Several other paths were also reported to have slid on several aspects of Mt Roberts. Towards the end of this event the Berhands path slid. Although this avalanche probably started as a dry slab avalanche near the summit elevations it quickly turned into a wet avalanche at lower elevations. This slowed the slide considerably and it then started to follow the terrain. The transverse gulley at the bottom of the avalanche path which had a fair amount of snow in it still caught most of the slide and directed it towards the south. This natural avalanche stopped below Judy Avenue and above Troy Avenue. It stayed North of the closed road gates and did not affect the urban residents in the avalanche path. As it was near dark I was not able to see how much of the starting zone released. If not all of the starting zone released there is still natural avalanche potential in this path. Please do not go up into the area to look or to walk your dogs above the close road gates. It is still questionably unsafe in that area. There are still several other avalanche paths in the urban enviroment that have not slid and the potential remains. Avalanche danger is HIGH at this time and will remain HIGH for the next 48 hours. Even though some paths have shed. They will continue loading overnight. And with multiple weak layers in place there is potential for avalanches to release at deeper depths than we have seen previously. Size during this type of an event is hard to predict but it is fair to say they will not be small... Danger will remain high and avalanche sizes will vary from path to path. Do your best to avoid travel in avalanche prone areas for the next 48 hours. Limit your time along places such as Thane Road, The Flume and Perseverance Trail. Recognize the White Path has not slid yet nor have the other urban paths from the Berhands Path all the way over to the White Path just North of Wickersham Ave. Backcountry danger is also quite HIGH! I dont think you would find me skiing in the backcountry today folks... Take a day to hide away... and live to ski another day... Potentially destructive natural avalanches likely to come near or reach developed areas, natural and human triggered avalanches likely. ]]>Thu, 02 Feb 2012 00:00:00 -0900http://www.juneau.org/avalanche/index.phphttp://www.juneau.org/avalanche/index.php
The National Weather Service Forecasts- REST OF TODAY...VERY WINDY. RAIN. SNOW LEVEL LOWERING TO 1300 FEET IN THE AFTERNOON. HIGHS AROUND 46. SOUTHEAST WIND 25 TO 40 MPH WITH GUSTS 70 MPH...THEN DECREASING TO 20 MPH WITH GUSTS TO 45 MPH IN THE AFTERNOON. TONIGHT...RAIN SHOWERS IN THE EVENING THEN SNOW SHOWERS LIKELY LATE. SNOW ACCUMULATION UP TO 2 INCHES. LOWS AROUND 30. SOUTHEAST WIND 10 TO 15 MPH. SATURDAY...COLDER. SNOW SHOWERS IN THE MORNING...THEN ISOLATED SNOW SHOWERS IN THE AFTERNOON. SNOW ACCUMULATION UP TO 2 INCHES. HIGHS AROUND 34. SOUTHEAST WIND 10 MPH SHIFTING TO THE NORTHEAST IN THE AFTERNOON. The Mt Roberts Tram JAWS temperature gauge reached its warmest temperature since Oct. 18, 2011 at 3am last night at 44f degrees. Although precipitation totals have not reached their forecast amounts we have received about .5" of precip in the last 24 hours. Winds have been blowing from 25-65 at the Tram Summit out of the SSE while Eaglecrest winds have been 40+ since midnight and are now in the 60-90mph range. Driving winds and the warmest temperatures we have seen in quite some time accompanied by todays rains with as much as another .5" of precip throughout the day will keep avalanche danger at HIGH. Potentially destructive natural avalanches likely to come near or reach developed areas, natural and human triggered avalanches remain likely. Temperatures are forecast to continually fall throughout the day and rain and wind rates are forecast to continually decrease. By this afternoon into this evening we should be back in a freezing cycle and things will start to stabilize once again. It will take a little time to do so as the snowpack, especially in the lower mountain regions, is quite rain saturated. We went through a large natural avalanche cycle from Wednesday afternoon into Thursday Afternoon with most all avalanche paths in the urban enviroment sliding. A few paths remain and will be quite questionable throughout the day today until things start to cool off significantly. One of those paths is Chop Gulley which comes down across the Flume and Perseverance Trail. This path starts at the highest elevation of any of our urban paths and has more snow than any other place in our region. Today is a great day to once again limit your travel through avalanche zones. By tonight into tomorrow we expect to see some additional stabilization and things should start to return to normal. Thanks for paying close attention to the conditions and HAVE A GREAT DAY. ]]>Fri, 03 Feb 2012 00:00:00 -0900http://www.juneau.org/avalanche/index.phphttp://www.juneau.org/avalanche/index.php
CBJ 6pm Updated Avalanche Forecast: ...WINTER STORM WARNING IN EFFECT UNTIL 6 PM AKST MONDAY... .TONIGHT...SNOW. SNOW ACCUMULATION 4 TO 8 INCHES. LOWS AROUND 27. SOUTHEAST WIND 10 TO 20 MPH. .MONDAY...SNOW...MIXED WITH RAIN IN THE AFTERNOON. SNOW ACCUMULATION 3 TO 7 INCHES. STORM TOTAL SNOW ACCUMULATION OF 7 TO 15 INCHES. HIGHS AROUND 35. EAST WIND 10 TO 20 MPH. Updated NWS winter storm-warning calls for significantly more snow, with an additional 10-20 inches over the next 24 hours. We have received several inches since this morning. Winds will be out of the East 10-20mph, and have been peaking near 30mph out of the South since early this morning. Temperatures will remain near or below freezing at sea level. We had reports yesterday of some upper elevation point releases in the Thane and Cross Bay paths. Additionally, stability near our Urban starting zone elevations was reported to be good. The dry snow has been running far and fast, especially with most gullies and alders so well covered at this point in the season, but there are lee surface deposits varying from unconsolidated snow to wind packed slab. Avalanche Danger has been moved to CONSIDERABLE given the quantity of snow being called for in addition to moderate East winds. Expect Westerly slopes, including our Urban start zones, to be loading significantly throughout the night. The wind-driven new snow may create a significant hazard. Additionally loading of the previously cross-loaded start zones could trigger a slide that steps down below the wind slab from this last week, making a larger slide. Natural avalanches in our Urban paths capable of causing destruction may reach developed areas, and human triggered avalanches are likely. At middle elevations on shaded or slopes oblique to the sun above the snow line, there is a surface hoar layer that may pose a hazard beyond new snow instability. Avoid Perseverance and Flume Trails through the forecasting period and possibly beyond. ]]>Sun, 26 Feb 2012 00:00:00 -0900http://www.juneau.org/avalanche/index.phphttp://www.juneau.org/avalanche/index.php
The National Weather Service Forecasts- TODAY...RAIN. HIGHS AROUND 41. SOUTHEAST WIND 10 TO 20 MPH. TONIGHT...RAIN. SNOW LEVEL 1300 FEET LATE. LOWS AROUND 35. SOUTHEAST WIND 10 TO 15 MPH. FRIDAY...SNOW AND RAIN. NO SNOW ACCUMULATION. HIGHS AROUND 40. SOUTHEAST WIND 10 TO 20 MPH. Since noon on the Monday we have received about 65cm of new snow at the Mt Roberts Tram Summit. The first 24 hours brought about 30cm (1') of new snow. Then we saw rain to those elevations and quite a bit of settlement. Yesterday around noon temperatures dropped just enough for the snow to start accumulating at the Tram Summit once again. In the last 18 hours we received about 38cm of new snow(15"+). This came from 40mm of precip.(1.6"). Our 3 day Tram Total for precip is over 90mm (3.6") and continuing on that 1+" per day average. Eaglecrest is showing slightly less but still has over 10" of new snow in the last 18 hours at the UAS Weather Station. Winds have been moderate to considerable throughout the storm. We have seen 20-30 knot winds along the channel as where the Eaglecrest gauge has been showing higher winds with averages from 25-40knots. Once again mostly out of our traditional SSE Loading direction. Watch for loading on N NW facing slopes. With 1.28" of precip in the forecast for the next 24 hours, 2.05" of precip in the forecast for the next 48 hours and warming temperatures avalanche danger will remain HIGH. Potentially destructive natural avalanches likely to come near or reach developed areas, natural and human triggered avalanches likely. This recent storm is placing a lot of stress on the snowpack in place. Yesterdays mitigation results along Thane Road showed us the lower weak layers are staying innitially strong. But as we continue to add stress over the next 48 hours we have multiple layers of concern that may become reactive.]]>Thu, 08 Mar 2012 00:00:00 -0900http://www.juneau.org/avalanche/index.phphttp://www.juneau.org/avalanche/index.php
The National Weather Service Forecasts- TODAY...WINDY. RAIN IN THE MORNING...THEN RAIN AND SNOW SHOWERS LIKELY IN THE AFTERNOON. NO SNOW ACCUMULATION. SNOW LEVEL 1400 FEET IN THE MORNING. HIGHS AROUND 38. TEMPERATURES SLOWLY FALLING IN THE AFTERNOON. SOUTHEAST WIND 15 TO 25 MPH WITH GUSTS TO AROUND 40 MPH DECREASING TO 10 TO 15 MPH IN THE LATE MORNING. TONIGHT...RAIN LIKELY. SNOW LIKELY LATE. SNOW ACCUMULATION UP TO 2 INCHES. SNOW LEVEL 500 FEET IN THE EVENING. LOWS AROUND 31. SOUTHEAST WIND 10 TO 20 MPH. SATURDAY...SNOW SHOWERS LIKELY...MIXING WITH RAIN IN THE AFTERNOON. SNOW ACCUMULATION 1 TO 2 INCHES. HIGHS AROUND 38. NORTHEAST WIND 10 TO 20 MPH. We have received 80mm (3.2")of precipitation in the last 48 hours. This left about 40cm (16")of new snow at the Mt Roberts Tram Summit and slightly less at Eaglecrest. This is quite a bit of high density snow for a 48 hour period and places tremendous stress on the weak layers that were previously in place. If you look further back to Monday afternoon we have received 110mm (4.2") of rain in 3.75 days. This brought a total of almost 70cm (2'4")of new snow since Monday. This deposited huge wind slabs in places. Winds averaged 20-30 knots out of the SSE during most of this cycle. Last night they picked up to 30-60 knots from 8-12pm. Temperatures warmed yesterday to +1 at the tram summit and right to 0 at the Eaglecrest Summit. Todays forecast calls for as much as another 1" of rain in the next 24 hours and temperatures remaining warm through the morning. Avalanche Danger is HIGH at this time. Potentially destructive natural avalanches likely to come near or reach developed areas, natural and human triggered avalanches likely. Temperatures and precipitation rates are expected to start to fall later today. This should start to allow our snowpack to stabilize further. Yesterday at Eaglecrest the avalanche control was producing huge results with slabs releasing from 1-5' deep! Today you can assume that skier triggers of those same depths may be possible in places in the backcountry. This is spookey snow... the kind that may not avalanche on the first or second guy down a slope... it may be waiting for you to break up the slab a bit... but once it gets moving it was traveling far and fast... a place you dont want to be... Avoid steep, open, windloaded slopes, unsupported convex rolls and terrain traps. Things will continue to get better. But today is still a great day to use EXTREME caution if you choose to be in avalanche prone areas. Limit your danger by simply limiting your exposure. Give conditions another day to stabilize and tomorrow will be a much safer, cooler, more powder filled day.. USE CAUTION MY FRIENDS... Were almost out of the woods with this high danger avalanche cycle...]]>Fri, 09 Mar 2012 00:00:00 -0900http://www.juneau.org/avalanche/index.phphttp://www.juneau.org/avalanche/index.php
The National Weather Service Forecasts- TODAY...RAIN. HIGHS AROUND 40. EAST WIND 10 TO 20 MPH. TONIGHT...RAIN. LOWS AROUND 35. EAST WIND 10 TO 20 MPH. TUESDAY...RAIN...HEAVY AT TIMES. HIGHS AROUND 39. SOUTHEAST WIND 5 TO 15 MPH. Tempeatures rose by 7c over the last 4 days and 4c degrees over the last 48 hours. Temps went above freezing at the Mt Roberts Tram Weather Station yesterday morning around 10am. Precip rates have been moderate over the last few days with 40mm (1.6") in the last 72 hours. 1" of which came in the last 48 hours and .66" of which came in the last 30 hours. You can see precipitation rates are slowly rising. Winds have been considerable over the last 24-48 hours blowing out of the SSE from 20-30mph. Yesterday on Douglas Island the winds picked up additionally blowing to 40 and gusting higher. This added to some windloading on NNW facing slopes only at the very upper elevations. During the last 48 hours at the UAS Site which is located in a valley that will hold the cool air a little longer we lost only a cm or two of snow. At the Mt Roberts Tram Weather station which is located along the channel we lost a little more snow, a total of 3" of snow over the last 48 hours. This is a good thing getting rid of some of the mass off our lower mountain avalanche runout zones and also allowing the upper mountain to settle dramatically. The word for the day is Warm and Wet. We have seen substantial warming in our region over the last few days. The warming slightly preceded the precipitation and the precipitation rates rose gradually which is a good thing. If we had seen more rapid warming with higher precip volumes we would have gone into a natural avalanche cycle more quickly. This warming accompanied by moderate precip rates has given the snowpack a little time to settle and develop drainage channels at lower elevations to help process the greater precipitation rates to come. This is not the case for the upper mountain just yet. We have been seeing freezing rains so there is still a need for drainage channels to establish. The NWS forecast calls for as much as 1.16" of rain in the next 24 hours and 1.75" over the next 30 hours. This is a substantial increase in precip rates. The temperatures are forecast to stay quite warm during this event with rain on snow all the way to our mountain top starting zones and beyond. Avalanche danger is HIGH. Natural and human triggered avalanches likely. I assume we will see the steep rocky sections of Mt Juneau and Mt Roberts releive themselves of snow. This has the potential to trigger deeper weak layers in the surrounding snowpack in places. Spatial variability is HIGH in the snowpack due to the high wind events we saw a few weeks ago. We have widespread areas of shallow snowpack that were still weak in places. I assume these will see full depth percolation rapidly an lower elevations and in areas with no anchors, on steep unsupported or convex slopes, they will releive themselves. Higher elevations will be taking more time and we may see some releases due to massive loading associated with these large volumes of precip. The trickier question remains in the pockets of deeper snowpack. Much of our deeper snowpack has been fairly stable. Should these areas develop drainage channels they may hang in there ok. But between now stress is being continually added. If these areas are under steep sections that releive themselves they too may be triggered or entrained (Incorporated and swept along its flow) due to the lack of freezing which creates poor bonds. This has the potential to develop fairly good sized avalanches which would be our current worst case scenario. This is especially a concern on our steeper longer avalanche paths such as Chop Gulley above the Flume Trail and Snowslide Creek above Thane Road. Please avoid spending time in avalanche zones today. Do not hike the Flume Trail. Do not park or walk along Thane Road. Minimize your danger by minimizing your time in avalanche terrain. Do not walk the trails above the Berhands neighborhood as well. I expect at some point over the next 24-36 hours we will see some natural avalanche activity. ]]>Mon, 14 Jan 2013 00:00:00 -0900http://www.juneau.org/avalanche/index.phphttp://www.juneau.org/avalanche/index.php
The National Weather Service Forecasts- TODAY...LOCALLY WINDY. AREAS OF FOG IN THE MORNING. RAIN. MIXED WITH SNOW AT TIMES IN THE MORNING. SNOW ACCUMULATION UP TO 1 INCH. SNOW LEVEL RISING ABOVE 1500 FEET LATE IN THE MORNING. TEMPERATURES STEADY AROUND 39 FALLING IN THE AFTERNOON. SOUTHEAST WIND 15 TO 25 MPH WITH GUSTS AROUND 45 MPH. STRONGEST WINDS NEAR DOWNTOWN JUNEAU AND DOUGLAS. WINDS DIMINISHING TO 15 MPH...THEN SHIFTING TO THE SOUTHWEST IN THE AFTERNOON. TONIGHT...MOSTLY CLOUDY. CHANCE OF SNOW...MIXED WITH RAIN IN THE EVENING. LOWS AROUND 30. SOUTHWEST WIND 5 TO 15 MPH. FRIDAY...MOSTLY CLOUDY. SCATTERED SNOW SHOWERS. SCATTERED RAIN SHOWERS IN THE AFTERNOON. HIGHS AROUND 33. SOUTHEAST WIND 10 MPH. We have had a fairly significant storm over the last 48 hours. Temps have fluctuated a fair amount during that time. Temps rose by 2c degrees back to the point of freezing at the Mt Roberts Tram Summit. Temps are expected to rise midday today with diurnal warming up to about the 2500' level. We have received 95mm (Nearly 4") of precip in the last 48 We have received 1' of new snow up high in the last 24 hours and over 20" of new snow at upper elevations over the last 48hours. This is a lot of moisture for this depth of snow. Almost double the average snow density. Windloading remains a factor with high winds driving this snow and loading lee slopes on West through North faces. After the first foot of snow we saw wind drifts reaching nearly 3' we could expect to see double that in certain mountain starting zones. We are expected to see as much as an additional .6" of precip in the next 12 hours. This combined with midday warming and driving winds and loading may be the trigger for a natural avalanche cycle. Avalanche Danger is HIGH at this time. Potentially destructive natural avalanches likely to come near or reach developed areas. Natural and human triggered avalanches likely. If you head out into the mountains today use extreme caution and be very conservative on your route selections. Avoid windloaded slopes. Keep your slope angle down. Avoid steep convex rolls, unsupported slopes, terrain traps, and skiing above cliffs. Please do not hike The Flume Trail. Please do not park or walk along Thane Road. Please do not walk in the avalanche zones above the Berhands Neighborhood. Limit your exposure by limiting your time in avalanche terrain. As we go into tonight and tomorrow conditions should start to cool off and avalanche danger should start to fall slightly. This is a fair load and will take time to settle and bond. Time is your friend! Use extreme caution through todays warming. Be Safe and have a great day.]]>Thu, 17 Jan 2013 00:00:00 -0900http://www.juneau.org/avalanche/index.phphttp://www.juneau.org/avalanche/index.php
...STRONG WIND THROUGH THIS MORNING... TODAY...INCREASING CLOUDS. LOCALLY WINDY. SLIGHT CHANCE OF RAIN IN THE LATE AFTERNOON. HIGHS AROUND 40. NORTHEAST WIND 10 TO 20 MPH. WIND GUSTS UP TO 40 MPH IN THE MORNING NEAR DOWNTOWN JUNEAU AND OUT OF INTERIOR PASSES. TONIGHT...CHANCE OF SNOW...THEN RAIN AND SNOW LIKELY LATE. SNOW ACCUMULATION TO 2 INCHES. SNOW LEVEL RISING TO 200 FEET. LOWS AROUND 28...THEN RISING OVERNIGHT. NORTHEAST WIND 10 TO 20 MPH. SATURDAY...RAIN LIKELY. SNOW LEVEL 900 FEET IN THE MORNING. HIGHS AROUND 43. NORTHEAST WIND 5 TO 15 MPH. Oh that north wind doth blow ... Outflow winds picked up throughout the day yesterday creating top loading in most of the channel slide paths and cross loading in all the gold creek/perserverance slide paths. The main hazard this morning continues to be direct loading of new snow. Numerous small and medium size slides were reported yesterday in fresh windslab, but none of them stepped down into deeper layers. The Flume and Perserverance trails should continue to be avoided. Avalanche Danger is HIGH this morning due to the likelihood of natural avalanches, but sizes are not expected to be large. Natural avalanches likely this morning, becoming less so when the wind dies off later today, potentially destructive avalanches unlikely to come near or reach developed areas. Except the Flume Trail and Perserverance Basin which should be avoided all day! Human triggered avalanches likely. Unstable slabs likely on wind loaded terrain getting more tender as the day goes on. In Urban Zones this is a good time to stay out from under avalanche terrain when possible. Backcountry Travelers need to select route with care and attention to wind loading locally. Extra caution is advised with particular attention to wind affected slopes, SE - W facing aspects.]]>Fri, 05 Apr 2013 00:00:00 -0800http://www.juneau.org/avalanche/index.phphttp://www.juneau.org/avalanche/index.php
The National Weather Service Forecasts- TODAY...SNOW AND RAIN IN THE MORNING...THEN RAIN IN THE AFTERNOON. SNOW ACCUMULATION TO 2 INCHES. SNOW LEVEL RISING TO 1200 FEET IN THE AFTERNOON. HIGHS AROUND 43. EAST WIND 5 TO 15 MPH BECOMING LIGHT AND VARIABLE IN THE AFTERNOON. TONIGHT...RAIN LIKELY. CHANCE OF SNOW LATE. NO SNOW ACCUMULATION. SNOW LEVEL 700 FEET IN THE EVENING. LOWS 30 TO 35. LIGHT AND VARIABLE WINDS. SATURDAY...SNOW LIKELY IN THE MORNING. RAIN LIKELY. LITTLE OR NO SNOW ACCUMULATION. SNOW LEVEL 1000 FEET IN THE AFTERNOON. HIGHS AROUND 43. SOUTHEAST WIND 10 MPH. We have seen 2.8" of precip in the last 48 hours at the Mt Roberts Tram Summit as of 7am today. The first 26 hours that came in the form of rain. Yesterday morning around 9 it switched around to snow until the noon hour at the tram summit then back to rain until about 9pm last night. Overnight at the Tram Summit elevations we received about 10" of new snow and it continuing to accumulate. Winds were from 10-25 out of our traditional SSE. Temperatures fell during this event until this 7am forecast. If all of this rain had fallen as snow at the upper elevations in our starting zones in theory you could have as much as 28-30" of new snow. That is probably not the case and yet there is definitely more snow in our starting zones than on the weather station gauges. Todays forecast calls for continued precipitation during a warming trend. With over .8" of precip in the forecast for the next 12 hour period during a warming trend avalanche danger is HIGH at this time. EXPECT TO SEE NATURAL AVALANCHES around the region as this big spring storm event probably did not bond real well on the old snow surface. Remember the old rule of 5 red flags of direct action avalanche danger... Warming, especially through the point of freezing... You got it... Winds in the loading range from 10-30mph... You got it... Recent precip amounts of more than 1" in 24 hours... and a forecast calling for nearly .1" an hour for the next 8 hours... YOU GOT IT>.. For the last two you have to get out in the field... If your traveling and you hear whoomphing, see shooting cracks or feel the snowpack collapsing... your there... And last but not least look for recent avalanches around the region. Even before last nights storm I saw the snow from yesterday morning avalanche out of the white path. If this weak layer is still present around other paths this new load is likely to trigger it... So far this snowfall event has been right side up... during todays diurnal warming expect to see this as an upside down storm event with Considerable precip and loading winds. Natural avalanches are likely. Human triggered avalanches are more than likely. Please avoid the Flume and Perseverence Trails. Please also consider avoiding Basin Road. Even though it takes a large avalanche to affect this area from the other side danger levels are rising. Please do not park or walk along the avalanche paths on Thane Road. Please also do not walk in the gated areas above the Behrands Neighborhood. Please limit your risk by limiting your exposure time in Avalanche zones. Please avoid avalanche zones through today and tonight until this storm trend subsides and conditions stabilize. Please use caution if you choose to play in the hills today. Its a good day to pick your terrain wisely and be conservative until this new snow has a chance to settle and bond. Enjoy a beautiful morning... Its SPRING! ;)]]>Fri, 26 Apr 2013 00:00:00 -0800http://www.juneau.org/avalanche/index.phphttp://www.juneau.org/avalanche/index.php
The National Weather Service Forecasts- TODAY...SNOW AND RAIN SHOWERS IN THE MORNING...THEN SCATTERED RAIN SHOWERS IN THE AFTERNOON. SNOW ACCUMULATION TO 1 INCH. SNOW LEVEL RISING TO 500 FEET IN THE AFTERNOON. HIGHS AROUND 42. SOUTHEAST WIND 10 TO 20 MPH BECOMING NORTHWEST 5 TO 15 MPH LATE IN THE MORNING. TONIGHT...DECREASING CLOUDS. SCATTERED RAIN SHOWERS IN THE EVENING. LOWS 20 TO 26. NORTHWEST WIND 10 TO 20 MPH. MONDAY...SUNNY. HIGHS AROUND 44. NORTHWEST WIND 5 TO 15 MPH. This has been a stormy week. We have received 5.3" of precip over the last 4 1/2 days. It turned to snow 3 days ago on my Mt Juneau gauge and we have received 31" of new snow since then. Sure to be more at summit elevations as my gauge is 1000+' below summit levels. The Eaglecrest mid mountain gauge is showing far less with only 20" of new snow but having been up there yesterday I can tell you mountain top totals are far greater. The Tram Summit is showing about the same coming in at that 20" mark. Since noon yesterday we have received 30mm of precip at the Tram Summit. This left us nearly 30cm of new snow (about a foot). Winds picked up yesterday during the event ranging from 20-50+mph. The forecast for today calls for rising temps and low volumes of continued precip through the 2pm hour. Actual precip totals have been far greater than forecast precip totals during this event. Yesterdays field evaluation revealed we have seen fairly widespread natural avalanche activity. Many slopes have failed and yet many have not. Pit work showed multiple weak layers at different levels and last nights snow and wind is sure to have created a new one as well as drastically increasing the load to the snowpack. Our loading rates have been near critical levels over the last 4 days. Anything that has not slid is questionable in stability. Even the slopes that have slid have reloaded and remain in question but at least the volumes are less. I am beginning to become more concerned with the urban paths. We have seen some natural activity but not with any larger slides and I am fairly convinced only a portion of the starting zones has released. Avalanche danger is high this morning due to continued loading and the heavy precip rates over the last few days plus the diurnal warming today as well as active windloading. If the forecast holds true precip volumes should start to decrease shortly. That would be a good thing. Temperatures around the region are predicted to fall by as much as 15+ degrees into tonight. This should start to help the snowpack bond as it settles out. Avalanche danger trend will decrease as we see cooling this evening and less precip but be aware windloading is going to remain a concern for a while longer even though the winds shold slow they will continue. Skiing yesterday was not that great and conditions were a little nerve racking.. The mouse trap is set folks... Please dont find yourself in the wrong place over the next 24-48 hours. Snowmobilers be aware you have even more ability to trigger these deeper heavier denser slabs. Please avoid avalanche prone areas over the next 24+ hours. Please limit your danger by limiting your exposure to avalanche terrain. Please continue to avoid the Flume and Perseverence Trails today. Please also do not park or walk along the avalanche prone sections of Thane Road. Please also do not walk above the gated sections above the Behrands Neighborhood. If you head into the backcountry today recognize there are 5 red flag indicators of direct action avalanche danger and ALL 5 are present today. PLEASE USE EXTREME CAUTION if you choose to head into the mountains. Use conservative route finding travel practices. Please choose your routes wisely. Please limit your exposure to terrain traps, areas above and below cliffs, creeks, gulleys, chutes or depressions. Please also avoid wind loaded areas. Most of our winds during this event were out of our traditional SSE> They switched around at the end of the cycle to the west... So recognize many slopes may have windloads. Avoid windloaded pockets near summit and ridgeline. Today is also probably a good day to limit travel in the Behrands neighborhood. We have seen enough snow that if we had a massive release we could start to see snow into our urban enviroment. Be safe out there Juneau and have a great day. ]]>Sun, 28 Apr 2013 00:00:00 -0800http://www.juneau.org/avalanche/index.phphttp://www.juneau.org/avalanche/index.php
The National Weather Service Forecasts- TODAY...BECOMING WINDY. RAIN. SNOW LEVEL 900 FEET RISING ABOVE 1500 FEET IN THE MORNING. HIGHS AROUND 45. SOUTHEAST WIND 15 TO 25 MPH. GUSTS AROUND 40 MPH IN THE AFTERNOON. TONIGHT...RAIN SHOWERS. LOWS AROUND 41. SOUTHEAST WIND 10 TO 20 MPH. GUSTS TO 35 MPH DIMINISHING IN THE EVENING. THURSDAY...RAIN. HIGHS AROUND 47. SOUTHEAST WIND 10 TO 20 MPH. We have received 27mm of precip at the Mt Roberts Tram Summit in the last 27 hours. This left behind about 24cm of new snow at that elevation. The Mt Juneau Weather Station is showing about 30cm. Things are stacking up quite rapidly and more is expected. The temps have not gone above the freezing point just yet at the tram summit and remain at 30f degrees. Winds during this event have ranged from 20-50mph. Adding windload to our slopes. Thane Road had a natural avalanche at 10:55 am. It did not reach the road. But this is an indicator that we have gone into a natural avalanche cycle. Todays forecast calls for about .85" of additional precip over the next 24 hours. With rising freezing levels. This should be enough to start more natural avalanches in places. Todays forecast calls for additional winds as well adding to the wind slab and upside down snowpack. Avalanche danger is now HIGH. Natural avalanches are likely. Human triggered avalanches are very likely as well. Please avoid The Flume and Perseverance Trail. Please do not walk or park along the avalanche prone sections on Thane Road. Please also do not walk in the gated sections above the Behrands Neighborhood. Be conservative. Please avoid spending time in Avalanche zones. ]]>Wed, 01 May 2013 00:00:00 -0800