Avalanche Forecast

Sunny, warm weather is expected on Thursday.

Loose wet avalanches, mainly involving any recent storm snow from Monday and Monday night, will be possible on any steep slope, especially during the warmest part of the day Thursday afternoon. Pay attention to the integrity of surface crusts formed overnight. Backcountry travel early in the day is recommended since conditions can change rapidly due to daytime warming. Watch for wet snow deeper than your boot tops especially on steep solar slopes during the midday and afternoon hours.

The likelihood of cornice releases will continue on Thursday from intense solar radiation and warming temperatures. Cornice releases can be unpredictable during the spring so avoid areas below cornices and remember that cornices can break much further back than expected along ridges.

Any wind slab deposits caused from the snow received Monday, in combination with moderate westerly winds should have mostly stabilized by Thursday and wind slab won't be listed as an avalanche problem on Thursday. However, continue to watch for signs of wind slab mainly on north to east facing slopes above treeline where extra caution is warranted.  Firm wind transported snow and snowpack cracking can be good signs of wind slab layers.

Although not listed as an avalanche problem, large, powerful glide avalanches can release unexpectedly so avoid areas below steep unsupported slopes or rock faces.

Avalanche activity on Thursday is not expected to be as extensive as during the warm weather last week which more closely followed a period of heavier snowfall and already caused consolidation and some stabilizing. Hence the moderate avalanche rating in all areas. But heat related small to large loose wet avalanches, cornice releases and glide avalanches will be possible on Thursday. You will need to be able to evaluate avalanche conditions on specific terrain features and change your plans if snow conditions are more dangerous than expected.

Weather and Snowpack

A large upper ridge dominated the weather last week through early Sunday, resulting in very warm and dry weather. A spring avalanche cycle occurred in most areas over this stretch, likely peaking Thursday or Friday during the warmest temperatures and lightest winds. After a stormy March, the snowpack has undergone significant settlement and multiple melt-freeze cycles over the last week.

A front moved across the Cascades early Monday morning, resulting in a period of mostly light precipitation, cooling and moderate westerly crest level winds.  Precipitation transitioned from rain to snow as cooling occurred, forming a generally good bond to the old melt freeze crust. Most east slope areas received storm snow amounts ranging from 2-6 inches as of Tuesday.

Another upper ridge is currently over the Northwest causing sunny weather and warm temperatures.

Frequent March storms have built unusually large cornices along many ridges.

No persistent weak layers formed earlier this winter are layers of concern as we transition to a spring snowpack along the east slopes. 

Recent Observations

NWAC professional observer Tom Curtis was out on the Wenatchee Ridge near Lake Wenatchee Wednesday, 3/30 in the 2-4000 foot range and found many slopes melted out. On slopes still holding snow he found natural and easily triggered, loose wet avalanches on all solar slopes in the top 15-20 cm of snow.

Tom was out yet again on Mt Lichtenberg near Stevens Pass on Thursday 3/31 and found widespread large natural loose wet avalanches on nearly all solar aspects with easy to trigger loose wet avalanches on non-solar slopes.

A report on Turns All Year for the Chiwaukums described big rollerballs and big resulting debris piles also on Thursday 3/31.