Avalanche Forecast

The active changing pattern will continue over the Northwest through the weekend.

A strong front will cross the Northwest on Friday night causing increasing moderate to heavy rain or snow and rising snow levels. A natural avalanche cycle seems possible on Friday night.

Stormy weather due to strong orographic west flow and heavy showers with lowering snow levels should be seen Saturday. The main concern during the day Saturday should be rapid snow loading and deep storm slab building especially in the alpine and near treeline and then to below treeline on many or most slopes. Rapid snow loading is generally accepted to mean more than 1 inch of snow per hour. Natural and triggered avalanche should be likely on Saturday.

Strong SW winds will veer to W behind the front later Saturday morning.  Expect rapid wind loading Friday night and throughout the day Saturday.  Strong winds should easily develop wind slab on lee slopes...and due to the strong winds wind loading will occur further downslope than during a more moderate event.   

Remember the danger ratings and icons are for the daylight hours. Less danger might be seen in areas that often receive less snow such as Hurricane and Crystal. The avalanche danger should still be limited at the lowest elevations by shallow snow and terrain and vegetation.

Sunny weather with warm temperatures were seen Sunday and Monday. This produced some small loose wet slides on solar aspects and crusts on more varied but not all aspects. Less warming was seen in the passes due to cooler easterly flow. 

Weak systems began to move to the Northwest about Tuesday with persisting cool offshore surface flow. This caused light rain or snow and a mix of precipitation in the passes.

A front moved across the Northwest on Wednesday. Snowfall at most NWAC sites near and west of the crest was in the 6-17 inch range with less at Hurricane and Crystal. An overall cooling trend Tuesday and Wednesday helped to bond new snow to older or crusted surfaces from Sunday and Monday and built mostly favorable new snow profiles.

An occluded front crossed the Northwest late on Thursday. NWAC sites near and west of the crest had snowfall mostly in the 3-9 inch range again with less at Hurricane and Crystal. This snow was generally wet and heavy with remarkably high water equivalents.

Avalanche control results from the ski areas were somewhat variable on Friday morning. Little was seen by the Mt Baker crew. The crews at Stevens and Alpental saw local 6-12 inch and one 2 foot heavy slab releases on lee slopes mainly via explosives. But those reporting from each crew said skiers would cause these releases from the right locations. Some of these avalanches entrained snow down to crusts from last weekend.

Westerly flow between the departing occluded front and the approaching system is maintaining mostly light snow showers near and west of the crest at fairly steady temperatures on Friday. This should generally maintain slab layers such as the above mainly on lee slopes.

Reports indicate that hoar frost seen early in this week generally didn't survive the recent changes or is not reactive. Generally stable crusts and melt forms or rounding non-reactive facets should be found in the mid and base pack in this area.