Yesterday strong Easterly winds combined with 13” of new snow have created storm slabs in the mid and upper elevations of Turnagain Pass. These newly formed slabs could vary in size from 1-2 feet thick and could be easy to trigger today. Due to strong winds yesterday these slabs may be wind loaded further downslope than expected and could catch you by surprise. Expect slabs to be thicker on leeward features and along gullies where the snow has been cross loaded. Cornices are also likely to be tender. In the alpine triggering a storm slab or cornice could also wake up a much larger and more dangerous avalanche deeper in the snowpack. Don’t forget we have had continued stormy weather and elevated avalanche danger for the last two weeks including periods of heavy precipitation (both rain and snow), strong winds, and lots of recent avalanche activity. These are all red flags warning signs the snowpack needs more time to adjust to it’s new load. Maintaining a conservative mindset and avoiding slopes steeper than 35 degrees is recommended.
Active wind loading was observed yesterday on Tincan early in the storm.
Above 2,500′ very little information is known about the snowpack, but we do know that 5-8′ feet of snow has fallen over the last two weeks and landed on weak faceted snow with crust(s) near the ground. Last week this set-up was very reactive and there were multiple remote triggered avalanches in Turnagain Pass. More time and information is needed to determine the sensitivity and distribution of the deep persistent slab problem. Likely trigger spots will be thinner area of the snowpack wear winds have stripped snow. Unless you have x-ray vision these thinner areas will be impossible to know. Finding a shallow spot could have devastating results. This type of avalanche would be unsurvivable. There may be no obvious clues to indicate instability and digging to find the weak layer could be challenging. Conservative route-finding will be essential due to the potential for large avalanches.
A snow pit at 2250′ yesterday found weak faceted snow near the ground to be reactive. This pit was intentially dug in a thinner area of the snowpack, a place where triggering a deep slab will be more likley. At this elevation (2250′) several crusts are forming within the snowpack which is helping to strengthen the slab and make triggering at this lower elevation less likely. In the higher elevations where drier snow has fallen little is known about how the weak layer and slab are adusting.
Yesterday a storm moved through our region dumping 13 € of snow (1.0 € H2O) at Turnagain Pass and similar amounts in Girdwood. Temperatures remained in the upper 30F’s at seal level and precip fell as rain to about 700′ until early this morning when temps cooled and about an inch of wet snow fell in the lower elevations. Strong Easterly ridge top winds averaged in the 20’s (mph) with some gusts reaching the 70’s mph. Winds decreased early this morning to 10-20mph.
Today expected scattered snow showers with up to 3 € possible. Precip may be in the form of light rain up to 800′. Temperatures could reach the mid 30F’s at 1000′. Southeast ridgetop winds may be gusty this morning, but are expected to depreciate mid-morning to 5-15mph today.
Tomorrow scattered snow showers are likely and winds are expected to be light to moderate from the East as a weak low moves over the Kenai Peninsula. A window of clear weather is forecasted for Monday before another round of rain and snow moves through our region. At this point there is a lot of uncertainty as to what type and how much precipitation we will see next week.
* Sunburst weather station is down due to loss of battery power.
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||31||13||1.0||38|
|Summit Lake (1400′)||30||3||0.3||11|
|Alyeska Mid (1700′)||30||13||1.16||31|
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||26||SE||20||76|
|12/10/19||Turnagain||Avalanche: Tincan and Sunburst from the air||CNFAIC Staff|
|12/10/19||Turnagain||Observation: Tincan||Nancy Pfeiffer|
|12/08/19||Turnagain||Avalanche: Tincan||Ryan Van Luit Forecaster|
|12/06/19||Turnagain||Avalanche: Sunburst||Billy Finley|
|12/04/19||Turnagain||Observation: Sunburst||A.Johnston-Bloom/ W.Wagner/ R.Van Luit Forecaster|
|12/03/19||Turnagain||Observation: Hippy Bowl||Nick Langowski|
|12/01/19||Turnagain||Observation: Tincan, All elevations||Eric Roberts|
|12/01/19||Turnagain||Observation: Tincan||Andy Moderow|
|11/30/19||Turnagain||Observation: Tincan Treeline Plateau/ Common Bowl/ Ridge||Eric Roberts|
|11/29/19||Turnagain||Observation: Sunburst Ob #2||Aleph Johnston-Bloom Forecaster|
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: email@example.com
|Area||Status||Weather & Riding Conditions|
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