Tetons

The General Avalanche Hazard is LOW at all elevations this morning and will rise to MODERATE by mid day. Despite clear skies, temperatures remained warm overnight. Sun and melt-freeze crusts formed but will rapidly soften. As the crusts breaks down wet, loose sloughs will become possible. The potential for larger surface slides will increase as the day warms although forecasted cloud cover may limit the degree of heating. Any substantial rainfall will also rapidly increase the hazard. Two weeks of above freezing daytime temperatures have greatly warmed the snowpack. The possibility of deeper instabilities such as wet slab avalanches running on smooth rock or grassy surfaces, or buried weak layers on more northerly aspects remains.

A cold front will move into the region by Tuesday evening bringing cooler temperatures and snow to the mountains. Snow will spread to the valley floor overnight. 2 to 4 inches of accumulation is expected in the Tetons by Wednesday morning. Heavier snowfall with 3 to 6 inches is expected in the Greys River Range and 1 to 3 inches in the Togwotee Pass areas. Winds will become strong with frontal passage overnight with ridge top winds from the Southwest at 30 miles per hour. Snowfall will become light and scattered during the day Wednesday with mountain temperatures reaching 30 degrees. Rain on the valley floors in the evening will turn to snow overnight with a trace to 1 inch of accumulation.With the coldest forecasted temperatures in over two weeks the snowpack will cool with strong surface crusts dropping the Avalanche Hazard to LOW Wednesday. The new snow, however, will hold heat in the older snow and any sun breaks will cause sloughing of the new snow and possibly entrain older snow increasing the Avalanche Hazard. Local areas with warmer temperatures could also see an increase in the chance of larger slides.