Seward & Southern Kenai Mtns

Archives
Issued
Fri, December 22nd, 2023 - 7:00AM
Expires
Sat, December 23rd, 2023 - 7:00AM
Forecaster
Mik Dalpes
Conditions Summary

Weekend Avalanche Outlook

Saturday, Dec. 23- Sunday, Dec. 24

Happy holidays from all of your Chugach forecasters!  With up to 1-3  feet of new snow and strong winds forecast, we are expecting to see dangerous avalanche conditions this weekend.  If the forecast verifies, natural and human-triggered avalanches are almost certain.  We recommend staying out of avalanche terrain until the snowpack can adjust to its new load.  

Roof avalanches:  With loads of snow on rooftops and a warm storm headed our way this weekend chances for roof avalanches will increase.  Keep an eye on children and pets and be mindful of the roof when entering and exiting buildings.

Recent Avalanches

The last known avalanche in the Seward area was observed Thursday, December 21, on a SE aspect of Resurrection South.  This slide likely occurred during the storm Tuesday and Wednesday (December 19-20) at the new snow/old snow interface.  There was also a widespread natural avalanche cycle observed on Sunday, December 17 that included loose dry and wind slab avalanches in the 2,000’ to 4,500’ elevation band.  These were observed on most aspects and were all new snow avalanches likely from the December 16 storm.  If you are seeing avalanches send us a quick observation, we would love to get more information from this zone!

Weather Recap:  It has been another exciting weather week on the Kenai.  There were two notable storm events this week.  The first was last weekend. From Friday through Sunday (Dec. 15-17),  the Seward mountains received 6-12” of snow.  The east winds increased Saturday, which resulted in the widespread natural new snow avalanche activity described above.  The second storm last week began on Monday and tapered off Wednesday bringing at least 13” to the Seward zone.  The north wind started to blow Wednesday night, December 20 through Thursday, December 21, which likely caused the wind slab avalanche observed on Resurrection South yesterday.  

Weather Forecast:  A Christmas storm is on the way and it is snowing in Seward as I write this forecast.  1-3’ of snow is forecast to fall above 1,500’ in the Seward and Lost Lake areas by Sunday morning.   Easterly ridgetop winds are forecast in the 10-40 mph range gusting to 60 mph.  Winds should calm by Sunday afternoon.  Temperatures should increase, potentially bringing rain to 1,500’ on Saturday, but the storm should cool off and temperatures look to decrease into the low 20’s F on Sunday bringing snow back to sea level as the storm tapers off. 

Forecasted snowfall totals from 3am Saturday-3am Sunday, December 23-24, 2023.  Image courtesy of the NWS.  12.22.23

Avalanche Problem 1
  • Storm Slabs
    Storm Slabs
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.
More info at Avalanche.org

A big storm has arrived to the Kenai.  With 1-3’ of new snow expected in the mountains by Sunday and sustained winds of up to 40 mph, both storm and wind slabs will be our main concerns this weekend.  This storm is starting cold and warming up, which will make for an “upside down” structure with a heavier layer of snow on top of a lighter layer.  This can increase the likelihood of new snow avalanches.  Expect to see storm slab avalanches in areas sheltered from the winds and wind slabs in areas that see wind loading. These types of new snow avalanches could be big enough to bury a person and are likely to be found everywhere if the precipitation and wind forecast verifies.  This storm is going to put a heavy load on the snowpack that does have a weak layer that is buried fairly deep and there’s a small chance this could cause a much larger avalanche.  (See video below).  We don’t think this problem exists in the entire Seward zone, but we found it in the Carter Lake area and we suspect it exists in the northern and western areas where there is less snow than the areas closer to the ocean.  The best way to completely avoid all of these avalanche problems is to stay out of avalanche terrain this weekend.  If you are getting out, we recommend riding slopes that are less than 30 degrees and staying out of runout zones.  

Lost Lake wind affected surface conditions before the storm arrived.  Photo Jordan Rymer 12.21.23

 

Weather
Fri, December 22nd, 2023
Friday, December 22, 2023
Weather Forecast Links:

NWS Point Forecast: Point forecast near Lost Lake.

NWS Avalanche Weather Guidance (AVG) forecast page: Zoom into the Anchorage bowl for special detailed winter forecast.

Windy.com Spot Forecast: Spot forecast for Lost Lake. (tip: scroll through models using the links at the bottom of the page, and change locations by clicking on the map).

Weather Stations

Grouse Creek Divide Snotel

Lost Lake Weather Station

Observations
Recent Observations for Seward & Southern Kenai Mtns
Date Region Location
04/16/24 Seward Observation: Lost Lake
04/10/24 Seward Observation: Lost Lake
04/03/24 Seward Observation: Snug Harbor
03/31/24 Seward Avalanche: Lost Lake
03/27/24 Seward Avalanche: Tiehacker Mountain
03/14/24 Seward Observation: Lost Lake via Snug Harbor
03/06/24 Seward Observation: Carter Lake
03/03/24 Seward Observation: Victor Creek, 1k – 1.6k elevation
02/29/24 Seward Observation: Carter Lake
02/26/24 Seward Avalanche: Mt Marathon
Riding Areas

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This is a general backcountry conditions summary. This advisory does not apply to highways, railroads or operating ski areas.