Avalanche Forecast

Issued: Jan 18th, 2019 9:00AM

The alpine rating is high, the treeline rating is considerable, and the below treeline rating is moderate. Known problems include Wind Slabs.

Dan Goodwin,

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Summary

Confidence

Low - Intensity of storm Friday and Saturday uncertain.

Travel & Terrain Advice

Travel in avalanche terrain is not recommended when the danger rating is high. Be aware of changes in conditions with elevation changes. Avoid wind loaded features and convexities. Cornices will continue to grow and become less stable with the incoming precipitation and wind. Give them a wide berth above and below.

Avalanche Summary

No new avalanches have been observed or reported since the last bulletin.

Snowpack Summary

15-20 cm of new snow falling on Thursday combined with strong winds from the SE have created highly variable surface conditions. Windward terrain has been stripped to the previous strong melt freeze crust. Sheltered and leeward areas will have dense pockets of snow 10-30 cm deep. This new snow seems to be bonding moderately well to the previous old crust and is causing it to weaken and break down.

Snowpack Details

Surface: Wind affected. Scoured in exposed terrain and stiff pockets of new snow in leeward terrain. Upper: Dominated by a strong crust bridging lower layers. Mid: Well settled. Lower: Well settled.

Past Weather

The previous strong ridge of high pressure and associated fog and inversions have been replaced by another series of strong Pacific storms making landfall early Thursday morning. 15-20 cm of new snow fell through the day on Thursday with freezing levels around 1000 m.

Weather Forecast

FRIDAY: 20-40 cm of accumulation above 1000 m with freezing levels around 1200 m. Higher totals in the west. Winds SE strong to extreme later in the day. SATURDAY: 40-65 cm of snowfall, higher amounts to the north and west. Freezing levels around 1000 m. Winds SW extreme early in the day easing to moderate in the afternoon. SUNDAY: 0-3 cm of snow with freezing levels around 750 m. Winds light and variable.

Problems

Wind Slabs

An icon showing Wind Slabs
Expect to find reactive/touchy wind slabs in the alpine and exposed upper treeline on NW through NE aspects. Ridge crests and cross loaded terrain features should be assessed carefully. Slopes below cornices will be heavily loaded and likely could be triggered with a light load. These avalanches have the potential to be large in size (size 1-2+).

Aspects: North, North East, North West.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Jan 20th, 2019 5:00PM