Urban Avalanche Advisory

Current Advisory as of

February 3, 2023

Expires 7:00 AM the following morning.

Issued By Tom Mattice

Danger Level: 2 - Moderate
View Danger Definitions

Today's Discussion

Small volumes of snow and light winds continue around the region...  we have picked up over 1' of new snow at upper elevations in the region over the last 4 days.  Where winds started strong early in this event with a 2 days of notable winds...  the first 4" snow came in with SE winds and the second series of flurries followed with NE winds...  We have some level of wind slab built on SW-NW faces in the region.

The last 48 hours brought the majority of the snowfall and yet winds have been quite light.  Snowfall rates have not been all that high and temperatures have remained fairly steady and near freezing allowing for a more quickly stabilizing snowpack...

With continued light winds, continued light precipitation and a little warming today avalanche danger remains MODERATE in the region with natural avalanches unlikely and yet human triggered slides, especially wind slabs may be possible.

Should we see enough warming or precipitation today you may also see loose wet avalanches at lower elevations in the region and yet these are not forecast to raise to upper elevations or be of notable size.  These should be small events should they occur.

The storm slab remains fairly loose and unconsolidated which should limit its activity.

Currently its 31f at the tram up from yesterdays 25f.  They picked up 3-5" on the gauges from .2" swe which is fairly light dry snowfall.  Winds peaked at only ese19mph.  Even Sheep mountain only saw winds to s28mph.  Enough to drive wind loading and yet still lighter than average.

Eaglecrest also picked up a few inches of snow and yet less than the tram with only .16" SWE.  Eaglecrest is currently 27f on summit up from 25f.

Todays forecast is calling for a short spike in temperatures during the early part of the day and should be cooling again by 4pm this afternoon.  Dangers will be hightened during this warming.  We may see a little precipitation and yet volumes should be limited.

Please recognize that should temps rise beyond forecast or should precipitation levels exceed forecast volumes  you may see an increase in avalanche danger levels and activity...  and yet if the forecast holds dangers are to remain moderate with little to no natural activity today.  Yet remember this snow did not bond all that well to the old snowpack surface and human triggered avalanches may be possible in wind loaded areas.

 

The National Weather Service Forecasts-

Today- Mostly cloudy. Numerous snow showers early in the morning. Patchy freezing fog in the morning. Scattered snow showers. Scattered rain showers in the afternoon. Snow accumulation up to 1 inch. Highs in the mid 30s. Northeast winds 10 to 15 mph.

Tonight- Mostly cloudy. Scattered rain showers in the evening. Scattered snow showers. Near steady temperature in the upper 20s. Northeast winds 10 to 15 mph.

Saturday- Cloudy. Scattered snow showers in the morning, then numerous snow showers in the afternoon. Snow accumulation up to 1 inch. Highs in the lower 30s. East winds around 10 mph.

Primary Avalanche Problem

Wind Slab

Problem Type:Wind Slab
Avalanche Size:Large
Avalanche Likelihood = Possible
Avalanche Trend = Decreasing Danger

Description

The current storm system started up on the 30-31st with 4" new snow and winds to se24 and se34 at Eaglecrest.  Enough to drive some wind loading...

On the 1st we picked up another 2-4" snow this time with n28mph winds along the channel and ne27mph at Eaglecrest...  once again not terribly strong winds and yet with new snow enough to drive some wind loading...

Yesterday we again picked up closer to 5" around the region again with winds to n41mph at the tram and ne22mph at Eaglecrest.  More wind loading along the urban paths than on Douglas...

Coming into today another few inches of snow and se20mph winds along the channel with ese24mph winds on Douglas...  still enough to continue loading and yet all of these events have been light on precipitation and moderate winds...  but over this same time we built storm slabs up to 1' thick in places now...  so you could have wind slabs of even greater size in the region that could potentially still be human triggered.

As we go into tonight and tomorrow conditions will dry out a little and temps will cool again decreasing danger levels over the next 24-36 hours.  Winds tomorrow should also be mild...  reducing avalanche danger over time.

Learn more about Wind Slab.

Secondary Avalanche Problem

Storm Slab

Problem Type:Storm Slab
Avalanche Size:Large
Avalanche Likelihood = Possible
Avalanche Trend = Decreasing Danger

Description

We see above for general details.  The Storm slab is up to 1'+ thick in places now and today is calling for moderate winds, warming, and some precipitation...  we do not expect to see natural avalanches occurring and yet should we see warming greater than forecast or more precipitation than expected we may see some level of natural activity...  yet the current forecast is not calling for this...

At lower elevations today loose wet avalanches remain possible with todays warming and continued precipitation and yet once again, low in elevation and small in  size.

As we go into tonight and tomorrow conditions will dry out a little and temps will cool again decreasing danger levels over the next 24-36 hours.

Learn more about Storm Slab.

Today’s Avalanche Tip

Please recognize this is an urban advisory and not a full backcountry avalanche forecast.  We try to discuss trends around the region but to head into the hills you need to be able to make your own educated avalanche decisions.

We recommend everyone playing in the backcountry take a level one avalanche course at minimum.

To understand more about the conditions in the backcountry in the region please go to the Coastal Alaska Avalanche Center at http://CoastalAkAvalanche.org to share your snow and avalanche observations.

Please do your part in sharing valuable information and remember as a community, the more we know, the safer the snow.

Be safe and enjoy a great day.

A little information for you on avalanches and loading rates:

https://avalanche.org/avalanche-encyclopedia/snowpack/snowpack-observations/signs-of-instability-red-flags/heavy-snowfall-or-rain/loading-loading-rate/