Avalanche Forecast

An occluded front pushing through Wednesday night should be followed by light showers on Thursday morning and a cooling trend. A surface low tracking inland near the Oregon/Washington border mid-day Thursday should provide a burst of moderate snowfall in the afternoon and evening hours for the southern Washington Cascades, followed by strong W-SW winds. Lighter snowfall is expected further areas further north during the daylight hours. 

New wind slab should build on lee slopes near and above treeline Thursday afternoon and evening. Watch for new firmer wind transported snow mainly on lee N to SE slopes near ridges. 

Storm snow with a cooling trend Wednesday night and Thursday should generally bond well to surface snow comprising of wet grains or various crust layers. Heavier precipitation rates Thursday afternoon and evening should increase the storm slab likelihood especially for the southern Washington Cascades.  

Despite the cooling trend, loose wet avalanches will remain possible below treeline Thursday especially on steeper slopes. Watch for wet surface snow deeper than a few inches that usually precede loose wet avalanches or other triggered or natural loose wet avalanches. 

Glide avalanches also won't be listed as a problem but avoid areas below steep rocks still holding snow since these slopes can release at unpredictable times. Look for glide cracks in steep terrain to offer clues of the slab undergoing downhill creep. 

Weather and Snowpack

Dry weather with the warmest temperatures of the winter occurred February 7-10th with mild temperatures and high freezing levels. 

A pair of warm fronts passing through Thursday, Feb 11th through Saturday, Feb 13th brought a wide range of snowfall with the biggest storm totals of a foot to 18 inches at higher elevations stations and Mt. Baker and Paradise. 

Rain and mild temperatures dominated along the west slopes Sunday and Monday with snow mixed in at the beginning and end of the event. NWAC sites in the near and below treeline recorded 2-6+ inches of mostly rain over the 2 days ending early Tuesday morning. The Paradise station recorded over 5 inches of precipitation (mostly rain) in the 24 hours ending Monday 4am!

Mild temperatures with spotty light rain were seen on Tuesday and Wednesday. 

The upper snowpack should consist of a mix of crusts and wet grains with no deeper instabilities of note.  

Recent Observations

Reports from the Mt Baker pro-patrol Saturday and Sunday indicated the 19 inches of storm snow was reluctant to move during avalanche control. A few isolated wind slab pockets were noted along ridges otherwise the warming Sunday afternoon was causing a few loose wet slides on steep slopes. Reports from Stevens Pass Sunday indicated the 8-10 inches of storm snow became sensitive to ski triggers by Sunday late morning. These slides behaved as loose-wet avalanches as surface snow become increasingly wet.

NWAC pro-observer Dallas Glass was out near Mt Baker Monday and reported several recent large loose wet avalanches on steep north slopes near and below treeline. He also reported a large glide avalanche on a similar slope. Dallas was out again in the same area Tuesday and reported a widespread cycle of loose wet and wet slab avalanches occurred Monday night during heavy rain and snow on most aspects in the 4300-5000 foot range. A 1-2 inch surface crust by this morning had improved surface snow stability.

NWAC pro-observer Tom Curtis was near Stevens Pass Tuesday and reported many recent loose wet avalanches mainly on north to east slopes at about 5000 feet. A pit had water pooling above a crust at 35 cm with weak wet snow below the crust and an PST test indicating propagation below the crust. He also noted glide cracks on nearby slopes.

Mt. Baker and Alpental pro-patrols continue to report glide cracks and glide avalanches on steep rock faces in their areas due the continued mild temperatures and frequent rainfall.