The past week’s storm was accompanied by warm temperatures and a moderate southwest flow. Heavy wet precipitation kicked off a huge cycle of natural avalanches through Saturday. Reports from across the forecast area of wet slab, storm slab, and wind slab activity came pouring in. Temperatures cooled late in the week with lingering showers, and 6 to 30 inches of lighter, transportable snow at the surface was deposited as sensitive wind slabs on leeward slopes. Many of these slabs ran naturally Friday and Saturday or were kicked off intentionally by parties testing slopes. The remaining slabs on northeast aspects have gained strength and become more stubborn to trigger. Then the wind shifted post-storm to the northeast and blew some of the remaining soft snow onto southerly aspects. Winds yesterday were variable and localized wind slabs may have formed in other areas as well. Wind affected snow has been found lower in elevation than usual. These newer wind slabs have ranged from stubborn to touchy and may still take a day or two to stabilize.
Once the sun appeared again over the weekend, the intense solar radiation quickly warmed rocks and cliff bands as well as the surrounding snow. Reports of loose snow avalanches and roller balls began to appear Saturday and continued into Sunday afternoon. At lower elevations across the forecast area melt-freeze crusts were beginning to form. Temperatures will warm again a few degrees over the next two days; highs will reach the 40s even above 10,000 feet. Cloudy skies tonight and Tuesday may provide some shade, but may also prevent some of that solar energy from escaping into the atmosphere keeping the upper snowpack warm. This will extend the chance of wet point releases. Time of day is critical when evaluating your exposure to wet loose avalanches. East aspects will warm first in the morning and the action will follow the sun as it moves across the sky warming south and then west facing slopes in the afternoon. Be on the lookout for moist surface snow, pinwheels rolling down around you, and steep rocky terrain.
