Avalanche Forecast

Fair - Intensity of incoming weather is uncertain

A warm front passes over this region late today (Tuesday) bringing light or locally moderate precipitation--say 10 to 15 cm between Tuesday evening and midday on Wednesday. Freezing levels will rise to approximately 1800 m during this time and strong southwesterly winds are expected. On Wednesday evening, a cold front will pass, bringing another similar pulse of snow (10-15 cm between Wednesday evening and Thursday morning) and freezing levels down to surface levels. Late Thursday and into Friday a ridge of high pressure develops, keeping things cold and mostly dry. Winds should ease to light by Friday afternoon.

A size 2 human-triggered avalanche occurred on Monday on a northwest aspect at 1700 m. The avalanche was triggered in wind slab; the fracture line was 30 cm deep. Several large cornice-triggered avalanches also occurred on Sunday and Monday. One stepped down into lower facet layers producing a crown up to 2 m deep.

Total snowpack depths are approximately 250 cm at treeline. Recent daily new snow amounts have not been particularly high in the last few days, giving the storm snow a chance to settle and gain a little strength. Strong winds have redistributed some of this snow into the classic lee areas in exposed terrain-behind ridgelines, summits and exposed rolls and features. A surface hoar/facet/crust interface from mid-December is well preserved and acting as a persistent weak layer. This is buried 100 to 150 cm deep and has been reactive to natural and human triggers. The increased depth is beginning to make triggering more difficult but bear in mind it also increases the size of anything that does go on this layer, which in turn increases the consequences.