Avalanche Forecast

Issued: Nov 28th, 2021 4:00PM

The alpine rating is high, the treeline rating is considerable, and the below treeline rating is considerable. Known problems include Storm Slabs and Loose Dry.

Chris Gooliaff,

Glacier.

Rogers Pass continues to get hammered by storms, and the brief respite in weather on Monday will be followed up by several more stormy days.

Avoid all avalanche terrain until the mountain slopes can adjust to this new, heavy load.

Summary

Weather Forecast

The message from meteorologists and their weather models is simple: snow and high freezing levels.

Tonight: Snow, 10cm, FZL 1600m, mod/strong SW winds

Mon: Flurries, 8cm, FZL 1600m, mod/strong SW winds

Tues: Snow, 30cm, FZL 1600m, mod/strong SW winds

Wed: Snow, 20cm, FZL 1800m, mod/strong SW winds

Thurs: Snow, 15cm, FZL 1700m, light W winds

Snowpack Summary

120mm of precip in the last 4 days, with mod/strong SW winds, has created fresh storm slabs at all elevations. The mid and lower snowpack is generally rounded and well bonded. Below 1900m the November 15th crust exists in the mid-snowpack. Early season hazards have been freshly buried below 1700m, slide over the lumps and bumps with caution.

Avalanche Summary

The past 3 days has brought a widespread avalanche cycle up to size 3.5 from steep, wind loaded terrain. Temps are continuing to rise with the snowfall, ensuring that the natural avalanches will continue rolling until things cool off and the snowfall ceases.

Artillery avalanche control Sun am saw numerous sz 3-3.5 avalanches run to valley bottom.

Confidence

Problems

Storm Slabs

Rapid snow loading has formed fresh storm slabs. Moderate SW winds will also contribute to slab formation in the alpine and exposed areas at tree line.

Avoid avalanche terrain during periods of heavy loading from new snow, wind, or rain.
The new snow will require several days to settle and stabilize.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 3.5

Loose Dry

As the new snow piles up, expect touchy loose dry avalanches in steeper terrain. These can be especially problematic in / above terrain traps

Avoid avalanche terrain during periods of heavy loading from new wind.
Be careful of loose dry sluffing in steep, confined or exposed terrain.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 2

Valid until: Nov 29th, 2021 4:00PM