Avalanche Forecast

An incoming frontal system on Tuesday should largely stall along the coast during the day with periods of rain and snow for the Cascades. More moderate precipitation and stronger transport winds should hold off until Tuesday evening and night. Mild snow levels initially seen away from the Passes should gradually lower as the precipitation rates increase in the late afternoon and evening. East winds through the Cascade Passes should keep snow levels below pass level Tuesday.    

Shallow storm and wind slab avalanches are possible by Tuesday afternoon as snowfall rates and transport winds increase later in the day. Northwest through East aspects should continue to see additional light loading near and above treeline Tuesday, but look for wind slab on a variety of aspects especially near the Passes. Watch for signs of firmer wind transported snow that can indicate wind slab layers near and below ridges. If storm conditions develop faster than expected, change your travel plans accordingly for the increased hazard. 

Shallow loose wet avalanches are possible Tuesday mainly below treeline on steeper slopes for areas away from the Passes that see warming or light rainfall initially, however loose wet avalanches will not be listed as a primary problem Tuesday.   

Deep storm snow from late December is now well settled, homogeneous and stabilized in the numerous recent snowpits dug throughout the region.

Fair weather for about a week over the New Year caused extensive surface hoar and near surface faceted snow. About 4-15 inches of snowfall over the west slopes last week buried the surface hoar and near surface faceted snow along with some wind loading and wind slab formation. Several small avalanches occurred on the Jan 3rd layer last week. 

Mild weather, sunshine and light winds over the past several days with above freezing temperatures in most areas have caused the Jan 3rd layer to bond and strengthen. NWAC pro-observer Ian Nicholson visited Chair Peak in the Alpental Valley on Friday. On a northeast slopes at 5500 feet he found the Jan 3rd layer to be gaining significant strength from earlier in the week. Tests gave hard results and did not indicate propagation with the layer difficult to distinguish about 6 inches below the surface.  

NWAC pro-observer Simon Trautman was also out on Friday near the Mt Baker ski area and found no signs of instability and no evidence of the layer that formed around the New Year for areas further south. Ski tests on steep slopes in all the elevation bands did not give results.

Ian was out again at Paradise on Saturday and generally found 2-3 cm melt form crusts over about 5 inches of snow from last week over the Jan 3rd layer. Snow pit tests gave moderate to hard results without propagation on Jan 3rd layer.

Light precipitation with a slight cooling trend was seen away from the Passes Monday, while light snowfall and steady temperatures were seen at the Snoqualmie and Stevens Pass.