Purcells

Strong winds, elevated freezing levels combined with periods of sun and a chance of snow/ and rain, will make for touchy avalanche conditions.

Fair - Timing, track, or intensity of incoming weather system is uncertain

An unsettled, winter-like weather pattern will continue through the forecast period. A weaker storm will make way to the Interior tonight and freezing levels will drop significantly in the wake of the cold front. As the front sweeps through, light-moderate precipitation will fall and ridgetop winds will be moderate from the west. On Saturday and Sunday, accumulated precipitation 5-20 mm with ridgetop winds blowing strong from the west and freezing levels steady around 2100 m. The general weather pattern is expected to bring multiple systems but the confidence in the exact timing, track, and strength of each system is poor.

On Thursday, wind and warming conditions were responsible for several natural slab avalanches up to size 3 from east and north aspects above 2100 m. There was also a report of a close call, skier triggered size 2.5 slab avalanche from the Dogtooth range. Extensive snowballing, and small loose wet avalanches were also reported from slopes below 2200 m. If some areas of the region see convective snow/ rain (20 mm) overnight Friday, and strong westerly winds, natural avalanche activity will likely continue on Saturday.

Recent warm temps, sunny periods and high freezing levels will make surfaces moist; with some crust recovery/ development above 2000 m. Below that elevation no significant overnight recoveries are expected. At treeline and above storm snow amounts from last weekend vary. The NW part of the region received up to 60 cm while the Dogtooth received around 30 cm and the far south received close to zero. This dense storm snow sits over the mid-March interface which consists of a series of crusts, old wind slabs, facets and surface hoar. Snow-pit tests have shown this interface to be fairly easy to trigger and likely to propagate. In exposed terrain, strong SW winds had redistributed snow into touchy wind slabs on leeward terrain features and slopes. Below this interface is the mid-February facet/crust interface. The mid-February layer has been dormant for some time, however; in neighboring regions it has been reactive. Persistent weak layers may be suspect in shallower snowpack areas.