Avalanche Forecast

Up to about 7-15 inches of new snow seems likely along the west slopes by Monday morning.

West winds aloft and a cool slightly unstable air mass should follow the front across the Northwest on Monday. This should cause orographic snow showers and up to another 6-12 inches of snow seems likely along the west slopes by the end of the day.

This is a lot of new snow.

New wind and storm slab seem likely to be the main avalanche problems along the west slopes on Monday.

New wind slab may be deep and is mostly likely to be found on northwest to southeast slopes. Firmer wind transported snow and snowpack cracking can be good signs of wind slab.

New deep storm slab is likely in areas where new snow rapidly accumulates for more than several hours. This is likely along most of the west slopes Sunday night and Monday!

Cloudy cool conditions on Monday may limit the development of loose wet snow but the sun is gaining power so watch for the development of loose wet snow on solar slopes.

Conditions are a bit hard to predict following the low pressure system and front on Monday. The avalanche danger may decrease a little on Monday due to a little less wind, some stabilizing of new snow and fairly cool temperatures. This forecast will take a conservative approach to the danger levels and the avalanche forecasts will get refined after new information becomes available on Monday.

Weather and Snowpack

Storms have moved across the Northwest almost every day or two the past couple weeks with fluctuating but generally moderate snow levels.

A storm last Wednesday and Thursday caused a warming trend that peaked Wednesday night with very strong west winds seen throughout the Cascade range. About 4-14 inches of snow accumulated on a new crust in most areas along the west slopes through Thursday morning. Additional accumulations were light Thursday except above 5000 feet in the Mt. Baker area where another foot of snow likely fell.

A front on Saturday caused west-southwest winds and another 1-10 inches of snow with the most at Baker, Crystal and Paradise ending Sunday morning.

A deep surface low pressure system is moving from the Olympic Peninsula to Vancouver on Sunday. A front is crossing the Cascades Sunday afternoon. This is causing stormy weather along the west slopes with strong shifting southeast to southwest winds and moderate to heavy snow in most areas.

The mid and lower snow pack along the west slopes should generally be a stable mix of crusts and layers of moist and rounded snow crystals.

Recent Observations

The Stevens Pass and Alpental pro-patrols reported an extensive natural cycle Wednesday night. As the sun poked out and temperatures rose Thursday, large loose wet avalanches, both natural and skier triggered, were reported at Stevens.

A report for the Alpental Valley for Saturday via the NWAC Observations also noted a large avalanche had run from Chair Peak likely on Thursday.

A ranger on Saturday above Paradise reported 16 cm of recent F snow on a crust from Wednesday, with little effect from wind, no results in pit tests and ski cuts, and good snow conditions.

NWAC ambassador Jeff Hambleton was near Mt Baker on Sunday and reported a 3 foot natural slab avalanche on a north slope at about 6000 feet on Mazama Peak. He also reported there were several ski triggered slab avalanches on the north side of Shuksan Arm which would be in the 4500-5000 foot range but details are lacking.

The Crystal pro-patrol on Sunday reported mostly small but widespread ski triggered 4-12 inch wind slabs on north to west slopes near the ridges due to strong southeast winds. A private party via email also reported sensitive wind slab of 6-12 inches on varied aspects at Crystal Mountain on Sunday.