Avalanche Forecast

A moderate cold front will approach from the west Thursday night and cross the Northwest on Friday morning. This will be accompanied by increasing winds, moderate rain or snow and slightly lowering snow levels. Showers following the front should decrease Friday afternoon. A convergence zone may enhance showers near Stevens Pass Friday afternoon.

New wind slab is likely on lee slopes. You should be most likely to trigger a wind slab on north to southeast aspects near and above treeline. Watch for signs of firmer wind transported snow or cracking snow.

New storm slab is also likely on sheltered slopes again mainly near and above treeline. This is most likely in any areas that receive an inch of snow or more an hour for at least a few hours.

It is now March and the sun is getting stronger. Watch for sun effects on new snow mainly on solar aspects but possibly aspects as well. Wet loose avalanches are becoming more likely if you see pinwheels or initial small natural wet loose releases.

In sheltered areas where the winds are not strong and the snowfall not heavy the increase in avalanche danger should be more limited. In such areas the cooling trend may also help create right side up layering with lower density snow near the surface.

Over the past month two major storm cycles moved across Northwest.

The first two week storm cycle ended 25 February and deposited about 9 feet mostly wet heavy snow at Hurricane and caused avalanches across the region.

The second week long storm cycle wound down last Sunday and produced similar water equivalents as the February cycle.  Water equivalents and snowfall for the the second cycle were about 4 inches and 2 feet at Hurricane. So this was a cycle of wet snow and rain. This produced avalanches again across the region including reports from Holden Village, Stevens Pass, Tumwater Canyon, Alpental and Snoqualmie with pass closures at times.

NWAC observers Tyler and Katie Reid last Friday at Hurricane reported wet and saturated upper snow pack layers and numerous wet loose avalanches to size 2. Warming effects had penetrated quite deeply into upper snowpack layers. Here is a video from Tyler and Katy at Hurricane on Friday.

Warm wet weather last weekend caused wet snow conditions and many wet loose avalanches at Hurricane with several cornice collapses as well as reported by NWAC observer Katy Reid on Sunday.

Cycles of daytime warming and night time cooling have generally been seen the past couple days. The upper snowpack has temporarily stabilized and no significant avalanches have been reported the past couple days in the Cascades. Rain crusts at or near the surface in many areas in the Cascades were generally firm and fairly thick Thursday morning and are only softening on Thursday afternoon. Similar conditions should be seen at Hurricane Ridge on Thursday.