Soft settled snow will easily move as winds pick up in advance of the approaching storm. Wind slabs may be tender and easily triggered in the Alpine. As the snow starts today this will only become more likely. Wind speeds are forecasted to be easterly 25-45 mph gusting to 60 mph. Look for cracking, drifting and blowing snow. Cornices may also grow and become more tender with increasing wind, new snow and rising temperatures.
As the snow starts to fall today it will land on very weak surface snow and is not expected to bond well. It is important to remember there is widespread surface hoar as well as small facets on almost surfaces from road level high into the alpine. Expect new snow to act as a slab fairly quickly due to this interface. As temperatures warm throughout the storm and the wind blows this may become even more pronounced. Rain or rain/snow mix falling on the old snow may produce avalanches as well at lower elevations. Look for red flags i.e. recent avalanches, cracking and collapsing (whumpfing). Pay attention to changing conditions!
Rimed surface hoar over soft settled (faceting) snow on Sunburst ridge. Photo: Kevan Dee
We have been tracking a couple of weak layers this season. Buried surface hoar from November 16th and December 15th have both produced avalanches. These layers are still buried in the snowpack in some terrain. In addition there is faceted surface snow and new surface hoar waiting to get buried. New snow load may cause avalanches that step down into old weak layers. This may not happen initially as the storm starts but should be a factor that is remembered as it progresses. We have a weak foundation/snowpack structure. Patience will be key in the next couple of days. We could see a large avalanche cycle if this storm really does it’s thing.
Yesterday was clear with some valley fog. Temperatures were inverted with single digits in the valleys and high teens at ridge tops. Winds were light. Last night the temperatures rose into the 20s and winds picked up this morning gusting into the 30s.
Today there is a Winter Weather Advisory for the forecast area due to a warm wet storm that is forecasted to move into the region late this morning. Easterly winds will increase with gusting into the 60s and 3-7 inches of snow is expected today. Snow may be heavy at times and there is uncertainty with how warm it will be. Rain may fall below 1000′. The storm is forecasted to continue tonight into tomorrow with an additional 6-10 inches of snow overnight and 4-6″ tomorrow. The brunt of the storm is forecasted to be this evening.
...WINTER WEATHER ADVISORY REMAINS IN EFFECT FROM NOON TODAY TO 9 AM AKST SUNDAY FOR TURNAGAIN PASS AND PORTAGE VALLEY... * LOCATION...TURNAGAIN PASS AND PORTAGE VALLEY. * SNOW...12 TO 19 INCHES FOR TURNAGAIN PASS. 8 TO 15 INCHES FOR PORTAGE VALLEY. * VISIBILITY...ONE HALF MILE OR LESS AT TIMES. * WIND...EAST WINDS 25 TO 45 MPH WITH GUSTS TO 60 MPH.
Snow showers will continue into early next week with a clearing and cooling trend towards the weekend.
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||15||0||0||24|
|Summit Lake (1400′)||7||1||.1||8|
|Alyeska Mid (1700′)||16||0||0||16|
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Sunburst (3812′)||Under repair||Under repair||Under repair||Under repair|
|Seattle Ridge (2400′)||15||SE||21||27|
|01/19/20||Turnagain||Avalanche: south facing aspect on 3800ft bump just northeast of 4940||Anonymous|
|01/19/20||Turnagain||Avalanche: Cornbiscuit & Magnum||Allen Dahl|
|01/19/20||Turnagain||Observation: Eddie’s||Kakiko Ramos-Leon|
|01/18/20||Turnagain||Observation: Sunburst||Ryan Van Luit Forecaster|
|01/18/20||Turnagain||Avalanche: Sunburst||Eric Roberts|
|01/18/20||Turnagain||Avalanche: North end Tincan trees||Heather Johnson|
|01/17/20||Turnagain||Observation: Tincan||Allen Dahl|
|01/16/20||Turnagain||Observation: Lynx Creek||Wagner / Van Luit Forecaster|
|01/13/20||Turnagain||Observation: Tincan||Ryan Van Luit Forecaster|
|01/12/20||Turnagain||Observation: Magnum West face||Levi Oyster|
Status of riding areas across the Chugach NF is managed by the Glacier and Seward Ranger Districts, not avalanche center staff. Riding area information is posted as a public service to our users and updated based on snow depth and snow density to prevent resource damage at trailhead locations. Riding area questions contact: firstname.lastname@example.org
|Area||Status||Weather & Riding Conditions|
This is a general backcountry avalanche advisory issued for Turnagain Arm with Turnagain Pass as the core advisory area. This advisory does not apply to highways, railroads or operating ski areas.