Avalanche Forecast

An upper ridge and surface high pressure should begin to strongly build west of the US west all the way to the Gulf of Alaska on Monday. Light snow showers on both sides of the crest should decrease and end on Monday. New snow along the west slopes from Sunday should be mostly in the 5-10 inch range above about 4-5000 feet by Monday morning.

A mix of likely dangerous winter and spring avalanche conditions is likely persist along the west slopes on Monday. The sun is getting much stronger and new snow will be reactive to solar effects.

Loose wet avalanches should be likely especially on solar slopes on Monday. Avoid avalanche terrain if you start seeing pinwheels or initial small natural loose wet avalanches. Be aware of terrain traps where even a small loose wet avalanche could have unintended consequences.

New wind slab of a foot or more is likely on lee slopes mainly in the near and above treeline on Monday. This is most likely on north to east slopes but possible on other aspects. Watch cracking and firmer or chalky wind transported snow. Remember that snow pits may not be helpful due to variability in the snowpack.

New storm slab layers may linger into Monday where there was rapidly accumulating snow for more than a few hours on Sunday. Pay special attention to slope convexities where storm slab is mostly likely to be triggered.

Cornices have grown large recently. Cornices can break much further back on ridges than expected and releases can be unpredictable during the spring.

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

Weather and Snowpack

Snow accumulations Wednesday to Friday following the last front varied based on elevation, with only a few inches below 4000 feet and 6-21 inches above. The most snow was received at the NWAC Baker and  Paradise stations. This snow was generally well-bonded to a moist crust buried March 22nd. 

A strong front and upper short wave crossed the Northwest Sunday morning. This is being followed by a large upper trough and cool unstable air mass Sunday afternoon and evening. Convergence Sunday afternoon has already shifted to near Snoqualmie.

Frequent March storms have built large cornices along ridges in many areas.

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

Recent Observations

On Friday the Baker pro-patrol reported natural slab activity above treeline on Mt. Shuskan but only small loose wet releases in area and a generally right side up upper snowpack.

NWAC pro-observer Lee Lazzara was out near Mt Baker on Friday and generally found 50 cm of storm snow on a rain crust from 3/21. He saw numerous loose wet avalanches on various aspects and despite warm temperatures some ski triggered loose dry avalanches were still seen on steep north slopes.

A professional guide observation from the Snoqualmie Pass area Friday morning indicated generally well layered and bonded storm snow with increasing potential for loose wet avalanches by late morning.

Further south Dallas Glass was out again near Paradise on Friday and found 60 cm of settled, bonded storm snow. He witnessed large rollerballs to 3 feet in diameter - watch out for those! Several small natural and ski triggered loose wet avalanches were seen on east to south facing slopes. There was significant wind redistribution of snow in the above and near treeline wind possible wind slab to 15 inches deep on north to southeast slopes.