Urban Avalanche Advisory

Current Advisory as of

March 18, 2024

Expires 7:00 AM the following morning.

Issued By Tom Mattice

Danger Level: 2 - Moderate
View Danger Definitions

Today's Discussion

The last week has been quite warm and wet around the region.  Much of the regions snowpack has developed runnels to help drain off the moisture and has settled a great deal.  This reduces avalanche dangers over time.

You may still have isolated areas at uppermost elevations where drainages are still being established.  If so, these areas have more questionable weakness.  Have you dug a pit recently to know if you have full depth percolation yet?  Without that danger lingers in the form of wet slab and glide avalanches.  Cornices also remain weak...

We saw a good deal of activity shortly after the storm.  Many of our weak areas have already slid.  Although not highly likely today, wet loose and wet slab avalanches remain possible.

With lighter precipitation today after several very warm days to summit with lots of rain to summit, avalanche danger remains Moderate.  Conditions drying out today and temps cooling tonight will allow danger levels to fall back to low potentially by tomorrow.

With above freezing temperatures  currently and light rains, avalanches remain possible although decreasing in likelihood.  We expect to see small wet loose avalanches as rocks and steep faces shed their winter layers.  Slab activity is also possible if our percolation finds a deeper weak layers.  We have also seen cornices failing around the region.  They remain weak and can potentially trigger slabs below them.

We will likely continue to see loose wet and wet slab avalanches today and yet they will not be nearly as widespread and should remain smaller in size for the most part.  Any place that has not already slid this week may still hold potential with the warmest temps of the season over the last 3 days.

Currently its 33f at the tram down from yesterdays 40 and Saturdays 51f!   Eaglecrest is showing 32.7f at Powder Patch down from yesterdays high of 40f and 31f on summit down from 38f.  Sheep mountain is at 30f again this morning and is more at low danger with the freezing temps in place once again. The last 3 days are the warmest temps of the season by far.

Winds are blowing se17-19 at the tram and se19-25 at Eaglecrest.  Winds peaked at sse32 at the tram and sse41 at Eaglecrest.  Sheep Mountain hit sse55mph.

We lost over 1.5" snow at the tram and 2.3" snow at eaglecrest while we picked up around .6" swe in the region.

Todays temps have cooled again to near freezing.  The forecast is calling for very light precipitation and minimal accumulation.  This should greatly reduce the likelihood of avalanches.

The National Weather Service Forecasts-

Today- Patchy fog in the morning. Near eaglecrest, widespread snow showers in the morning. Widespread rain showers. No snow accumulation. Highs in the lower 40s. Southeast winds around 10 mph.

Tonight- Mostly cloudy. Scattered rain showers and areas of fog. Isolated snow showers late. Lows in the lower 30s. Northeast winds around 10 mph.

Tuesday- Partly cloudy. Areas of freezing fog in the morning. Highs in the lower 40s. Northwest winds around 10 mph.

Primary Avalanche Problem

Loose Wet

Problem Type:Loose Wet
Avalanche Size:Small
Avalanche Likelihood = Possible
Avalanche Trend = Decreasing Danger

Description

With the warmest temps of some time over the last 3 days and continued light rains, loose wet avalanches remain possible.

Danger will remain until the temps cool back down below freezing and yet following several of the warmest days of the year with rains, we expect to see less activity today.

Tonight conditions dry out and temps fall additionally.  We expect to see dangers drop back to LOW by tomorrow.

Learn more about Loose Wet.

Secondary Avalanche Problem

Wet Slab

Problem Type:Wet Slab
Avalanche Size:Large
Avalanche Likelihood = Unlikely
Avalanche Trend = Decreasing Danger

Description

Following 5 days with very warm temps and rains to summit, wet slab avalanches remain possible today.

We saw a great deal of avalanche activity four days ago.  With reduced precipitation today and decreased temps we should see far less activity and yet any place that has not slid this week may still have instability.

It will take some time for the snowpack to drain and freeze again.  In the meanwhile danger lingers for wet slab activity although the likelihood of slides is decreasing a bit today with light precipitation and cooler temps.

With precipitation drying out tonight and temps falling, avalanche danger should fall to low by tomorrow as well  .

Cornice falls have also been noted around the region and several have been large enough to trigger slab avalanches beneath them.

Be aware that although not widespread, wet slab avalanches remain possible today.

Learn more about Wet Slab.

Today’s Avalanche Tip

Please continue to share your snow and avalanche observations with the Coastal Ak Avalanche Center at  http://CoastalAkAvalanche.org

From pages 9-13 there is some great information about wet snowpack and the spring process.

https://www.avalanchecourse.com/wp-content/uploads/2020/10/Snowpack-Pro-2.pdf