After an exciting day of several human triggered avalanches Saturday (with no one caught), yesterday we had no reports of avalanche activity, nor did we see any. If you know of an avalanche yesterday, please let us know HERE. Avalanches on Saturday were a function of 1-2′ of new snow from Jan 26 that fell on buried surface hoar. The snow was so light that it was only in scattered areas where it was cohesive enough to act like slab, and hence folks were able to trigger slab avalanches. The cold and clear weather is taking the light snow and continuing to loosen it though the faceting process. This is slowly eating away at remaining slabs out there. Despite this, there is still the possibility of finding and triggering one of these lingering slabs.
With cold and clear weather on tap this week, the big question for increasing avalanche danger will be what are the winds doing? There is plenty of loose snow available for transport and wind slabs could form quickly. So far the Turnagain Pass area has escaped any moderate/strong winds, but it does not seem that way in the Girdwood Valley. Ridgetop winds here increased overnight for a period into the 20’smph with gusts to 40mph, enough to transport snow. If you are headed to the Girdwood Valley area, be on guard for recent wind loading and potential for more dangerous avalanche conditons. Fresh wind slabs are likely to release on, or step down to, buried surface hoar under the Jan 26 snow and could be very touchy and run further than expected.
Quick hand pits to check how the top 1-2′ of snow is bonding is a good way to assess the conditions along your route. Additionally, watching for any shooting cracks, whumpfing, recent avalanche activity and any wind affect/loading patterns will be key for avoiding unstable slopes.
Surface conditions at mid elevations at Turnagain Pass – loose faceting snow with a new crop of surface hoar on top. (photo: Ray Koleser)
Watch your sluff – loose snow avalanches ‘sluffing’ is possible on steep terrain features protected from wind. As the cold weather continues to loosen and facet the top foot of the snow, we are expecting sluffs to become larger and faster by the day.
Triggering a deep slab is becoming unlikely, but is still not out of the question above 3000′. At these high elevation zones there are a variety of weak layers in the mid pack and near the ground. The most likely trigger spots are in thin areas in the snow cover, often near rocks, or where the slope rolls over. The Southern end of Turnagain Pass to Johnson Pass is more suspect for triggering a deep slab due to a thinner snowpack.
Yesterday’s weather saw valley fog up to 2,000′ with brilliant sunny skies above. Ridgetop winds were Northerly in the 5mph range and bumped up to 10mph overnight briefly with gusts to 20mph – the exception is Girdwood Valley where ridgetop winds from the NE overnight were in the 20’smph with gusts to 40mph. The inversion remains in place as temperatures stayed in the single digits in valley bottoms and in the teens F at mid and upper elevations.
Cold and clear weather (with valley fog) is again expected for today. The coldest station reporting this morning is the Granite Snotel near Johnson Pass trailhead at -13F, burr. The inversion will keep temperatures in the -10 – +5F range in valley bottoms and in the teens at the mid and upper elevations. Ridgetop winds are expected to be Northerly between 5-15mph.
Looking into the crystal ball, weather models have the cold air mass over Alaska in place for the remainder of this week and through the weekend – this means cold/clear weather with an eye for what the outflow winds are doing.
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||15||0||0||68|
|Summit Lake (1400′)||1||0||0||19|
|Alyeska Mid (1700′)||10||0||0||54|
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||16||E||3||17|
|01/26/20||Turnagain||Observation: Pastoral||Allen Dahl|
|01/26/20||Turnagain||Observation: Tincan trees and north side Tincan Ridge||Joe Kurtak, Anchorage Nordic Ski Patrol|
|01/25/20||Turnagain||Observation: Magnum||Ryan Van Luit Forecaster|
|01/25/20||Turnagain||Observation: Tincan||Eric Roberts/ Kakiko|
|01/25/20||Turnagain||Avalanche: Sunny Side of Seattle||Peter Wadsworth|
|01/23/20||Turnagain||Observation: TIncan||Eric Roberts|
|01/23/20||Turnagain||Observation: Goldpan||Allen Dahl|
|01/22/20||Turnagain||Observation: Sunburst||Adrian Beebee|
|01/22/20||Turnagain||Observation: Sunburst||Ryan Van Luit Forecaster|
|01/22/20||Turnagain||Observation: Seattle Ridge||W Wagner 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: 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.