Turnagain Pass

A low pressure system in the Eastern Gulf will combine with cool Northern arctic air over Southcentral Alaska today. There is a “fair amount of uncertainty on snow amounts” impacting Turnagain Pass, but expect snow totals to be anywhere between 5-15 inches.  Moderate Easterly winds (10-25mph) are also expected which could easily increase the avalanche danger throughout the day especially if snowfall intensifies. It will be important to adapt your travel plans to changing weather conditions and be on the lookout for any signs of instability; shooting cracks, whumphing sounds, or recent avalanches.

Don’t forget what this snow is falling on. A reactive layer of buried surface hoar from Nov.16 lies below 1-2 feet of old snow. This widespread layer exists on all aspects and has been the culprit in dozens human triggered avalanches over the last two weeks including the most recent on Sunday Nov.27 in Seattle Creek area. Today’s weather has the potential to re-load this weak layer increasing the likelihood for human triggered avalanches. Slab depths could be as thick at 1.5-3 feet thick depending on snowfall amounts. Cautious route choices and conservative decision making will be essential today.

Buried surface hoar is still a very visible layer and continues to be reactive in tests pits. Photo taken at 3200′ on a SW aspect of Tincan on 11/27 by Aleph Johnston-Bloom

Today’s new snow will be falling on weak old snow; snow that has been ‘faceting’ due to cold temperatures this week. The combination of wind and the possibility of higher snowfall totals (up to 15″) could produce storm slabs 1’ thick both in the alpine and at treeline.

Watch for glide cracks and remember to limit time under these, there have been a handful that released last week. *Several cracks have been opening in popular terrain like Tincan’s Common bowl and the SW face of Sunburst.