Avalanche Forecast

The past three days have seen the temperatures climb slowly back toward our normal cool/mild island winter levels. Light to moderate amounts of snow has fallen (10-20 cm in most zones). Winds have varied from NW to SE and have been light to strong.

Wednesday sees winds changing from the NW flow that has chilled us all, back to our regular SE flow that will blow in the next winter snow storm, with new snow falling Thursday through Friday. Wednesday - no new snow fall, winds strong NW falling to light SE, temps for 1500 m -4 to -7, freezing level 0 to 800 m.Thursday - 5 to 15 cm of new snow, winds moderate to strong SE, temps for 1500 m -6 to -1, freezing level 400 to 800 m.Friday - 5 to 20 cm of new snow, winds moderate to strong SSW, temps for 1500 m -4 to -5, freezing level 500 to 1000 m.

Avoid or be careful when entering wind loaded zones near ridge tops (especially open bowls and gullies) as wind slabs have and will continue to form over the next few days. Winds will come from multiple directions and load all aspects vs just the typical flow from the SE. Watch steep small bits of terrain associated with openings in the forest, as buried weak layers (surface hoar and facets) are now loaded with new snow and more is coming. Avoid exposure to terrain traps in these openings, as even small slides associated with them can magnify the potential for injury in these bits of small terrain.Multiple recent avalanche accidents in the states with many injuries and deaths have resulted from a well know touchy persistent buried weak layer. When interviewing survivors many mentioned their mental state and decision making processes (risk tolerance) were to some degree affected by Covid (either making them more numb to the warning signs due to their desire to get out, or a concern over not getting another chance to get out if restrictions to travel tighten). Be sure to do a good and thorough analysis of your decision making process, factor in weather and snowpack and don't forget the human factors.

From Sat Feb 13 until Tuesday night Feb 16 approximately 20 to 30 cm of new cold light snow fell on a old crust surface. Winds both from the SE and the NW have moved this light snow to either form wind slabs or strip zones down to the crust. Cold temperatures have eaten away at the thickness and strength of the crust that capped the two persistent weak layers in our mid snowpack to varying degrees based on location, aspect and elevation. Higher temperatures warmed the snow surface in below treeline elevations Tuesday leaving a slight crust and also saw trees shed their snow loads making travel in the forest unenjoyable.

Moderate - Many reports submitted for the entire forecast zone, weather models in agreement but uncertainly lies around the future sensitivity of the persistent weak layers that lie in our snowpack.