Avalanche Forecast

An upper ridge should drift across the Northwest on Friday. In the Olympics and Cascades this should cause some high clouds, light winds and gradually moderating temperatures west of the crest and at higher elevations.

Recent wind slabs should be primarily on N-W-S aspects. The benign weather should bring a little more stabilizing to these layers on Friday. Remember that firmer wind transported snow is always your best sign of wind slab layers.

The wind slab compass indicator below shows loading for the recent dominant wind direction but some areas may have experienced other loading patterns, so be alert on all terrain aspects for firmer wind transported snow.

Small loose dry avalanches might be possible in steep wind sheltered terrain but will not be listed as an avalanche problem. 

Weather and Snowpack

A pair of warm fronts moved across the Northwest Saturday and Sunday which allowed some relatively milder Pacific air to finally work its way east of the crest Sunday evening and night. 3-8 inches of snow fell through Monday morning along the east slopes. 

A weak low pressure system, tracking across southern Washington Tuesday morning through Wednesday afternoon produced 1-5 inches of snow in the central east to southeast Cascades with the most seen at the Lost Horse and Potato Hill Snotels in the southeast Cascade zone. E to NE winds increased Tuesday afternoon with another round of light snow developing over the southern Cascades.

Snow showers deposited another 2-4 inches early Wednesday in the southeast Cascades zone, with little or no snow in the north and central. 

Recent Observations

The NCMG were in the Hairpin Valley Monday and observed a natural loose cycle that likely occurred Sunday night. While a couple of storm layers were identified in snowpack tests, the only other direct sign of instability was a small wind slab triggered by cornice fall that again likely occurred Sunday night.

NWAC pro-observer Tom Curtis was on Mt Cashmere Wednesday and pulled the plug on continuing a tour due to the conditions observed. The sound of a natural avalanche rang out loudly in the valley Wednesday morning. It was estimated the slide released from a more westerly aspect near tree line. Other concerning observations included finding a reactive buried thin crust with faceted crystals below and a 25-35 cm 4F slab above. Cracks were shooting from skis and snowpit tests also indicated human triggered slab releases would be likely in this area so a retreat to ski another day was the safe call.

The NCMG were at Washington Pass on Wednesday and reported that wind slab from last weekend was primarily seen on E-SE terrain features and was becoming less reactive.

A couple reports via the NWAC Observations page are available for Wednesday. A report from Mt Cashmere indicated a shallow, variable snowpack with evidence of wind loading from last week. A collapse and snowpack cracking was seen on a southeast slope at 5300 feet due to a facet/crust layer at 35 cm down but these layers were not found to be widespread. A skier also reported 14-16 inches of snow and snowpack collapsing on Manastash Ridge on Wednesday.

NWAC pro-observer Tom Curtis was on Diamond Head at Blewett Pass on Thursday reported many wind scoured areas with previous wind transport primarily to W slopes. The 12/17 PWL was found at 30 cm down but was not reactive. Facets at the base of the snowpack were not giving test results.