Archived

Avalanche Forecast

Jan 11th, 2023–Jan 12th, 2023

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Alpine

4: High

The avalanche danger rating in the alpine will be high

Treeline

4: High

The avalanche danger rating at treeline will be high

Below Treeline

3: Considerable

The avalanche danger rating below treeline will be considerable

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Regions: Coquihalla, Harrison-Fraser, Manning, Skagit.

Dangerous avalanche conditions will develop with heavy snowfalls and rain.

Choose simple, low-angle, well-supported terrain with no overhead hazard.

Confidence

Moderate

Avalanche Summary

No new avalanches were reported in the region since Wednesday. Unstable wet loose snow was observed Tuesday on steep south and west aspects around 1600 m. Old evidences of loose wet avalanches, glide avalanches, and old wind slabs from the past weekend were still visible.

Snowpack Summary

Hard snow is found at upper elevations on open northerly terrain. Previous winds have scoured south-facing and east-facing slopes. Evidence of cross-loading is also found on any open slopes. A new melt-freeze crust has formed on the surface between 1000 and 1500 m. Moist snow is found at lower elevations.

In sheltered terrain, around 30 to 70 cm overlies a rain crust that formed in late December. The mid-snowpack is well-settled. The lower snowpack consists of several crusts with weak faceted crystals above and below that are beginning to heal and bond to each other.

Snowpack depths are roughly 145 to 185 cm at treeline and taper rapidly below 1500 m.

Weather Summary

A strong storm will push onto the region early Thursday and stall for 48h. Moderate snowfalls are expected before the subtropical flow brings warm air and heavy rain. Sustained high-freezing levels will last until Saturday.

Wednesday night

Cloudy, no precipitation, light southeasterly winds increasing to 40 km/h, freezing levels around 1200 m, low of -4C at treeline.

Thursday

Stormy 15-25 cm, rain at lower elevations, moderate southerly winds gusting 60 km/h, freezing levels at 1500 m rising to 1800 m, high of +2C at treeline. 20-30 mm of rain overnight.

Friday

Rain 15-20 mm, snow at higher elevations only, moderate southerly winds gusting 50 km/h, freezing levels around 2000 m, high of +3C at treeline.

Saturday

Cloudy, lingering flurries, moderate southwesterly winds gusting 40 km/h, freezing levels dropping to 1500 m, high of -2C at treeline.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Watch for changing conditions today, storm slabs may become increasingly reactive.
Minimize exposure during periods of heavy loading from new snow, wind or rain.
Closely monitor how the new snow is bonding to the crust.
The first few hours of rain will likely be the most dangerous period.

Avalanche Problems

Storm Slabs

At upper elevations, forecasted snow amounts will likely develop reactive storm slabs. Human-triggered avalanches will be likely, especially on leeward terrain features where deposits are deep. Closely monitor the bonding of the new snow with the underlying surface. Be aware that slab avalanches could step down to a crust layer and produce larger-than-expected avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 1 - 2