Avalanche Forecast

Light snow showers mainly near and west of the crest should end on Wednesday morning. A short relative break should be seen Wednesday afternoon.

New wind slab is most likely in the central and south Cascades. Watch for signs of firmer or hollow wind transported snow mainly on lee northwest to southeast near and above treeline.

New storm slab due to rapid loading is also most likely in the central and south Cascades in areas that receive more than a few inches of snowfall especially in areas with any warming like the Cascade passes.

Persistent weak layers had a good test from loading and warming over the weekend. On slopes that have not released on these layers, the likelihood of triggering is slowly decreasing, but the consequences are increasing as the slab depth increases. Wind or storm slabs that step down to persistent weak layer depths could become large enough to bury, injure or kill.

Also here is a heads up that a strong wet warm front is headed our way for Thursday.

Weather

Two fair weather periods earlier this month allowed surface hoar and near surface faceting to occur. These persistent weak layers were buried intact on Jan 3rd and 11th and have been reported through Monday from the Methow, the Icicle Creek area, the Blewett Pass area, the Nason Ridge area and the Chiwaukum range east of Stevens Pass. It's safe to say this layer is extensive throughout the east slopes.

A parade of weather systems this week added about .5-1 feet of snowfall to the east slopes from about Friday to Sunday.

A fairly vigorous surface low pressure and frontal system will cross the south Cascades Tuesday and Tuesday night. This should bring heavy snow to the south Washington Cascades, moderate snow to the central Cascades and lighter amounts of snow to the north Cascades.

Snow and Avalanche Observations

NWAC pro observer Jeff Ward on Sunday found the persistent weak layer on shaded slopes up to about 5000 feet in the Early Winters drainage. This layer was reactive prompting very cautious terrain selection of lower angled slopes. A video is here.

On Sunday the observer at the Scottish Lake High Camp in the Chiwaukums reported a natural 12 inch slab release on a southerly aspect around 5000 feet and easily identified two buried surface hoar layers in snowpits on a north-northwest slope at 5500 feet.

On Monday NWAC pro observer Tom Curtis was on Diamond Head near Blewett Pass in the 4-6000 foot range and found a persistent weak layer at 30-35 cm on north to east aspects with propagation indicated via PST and ECT tests. A 50 foot crack also released upon approach to a north facing starting zone indicating this layer remains reactive. A video is here.

A report via the NWAC Observations page from Wedge Mountain for Monday reports a skier was caught and carried but not injured by a 18-24 inch storm slab avalanche.

NWAC pro observer Tom Curtis visited the Rainy Creek drainage of the central east zone today and traveled from 2-5800 feet and found limited lingering wind and storm slab. He did not find any signs of lingering persistent weak layers.