Avalanche Forecast

Issued: Apr 2nd, 2016 9:00AM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is moderate. Known problems include Cornices, Loose Wet and Persistent Slabs.

ghelgeson, Avalanche Canada

Cariboos.

A Special Public Avalanche Warning remains in effect Sunday. While it's expected to be slightly cooler, the freezing level remains quite high (2200 m) which will keep danger ratings elevated.

Summary

Confidence

Moderate - Freezing levels are uncertain on Monday

Weather Forecast

Temperatures are expected to remain warm Sunday before beginning to cool Monday as a weak Pacific front injects cooler and cloudier marine air into the region. SUNDAY: Freezing level starting near 1300 m, climbing to 2200 m, light southwest wind, no significant precipitation expected, increasing cloud cover throughout the day. MONDAY: Freezing level beginning near 2000 m, lowering throughout the day to around 1500 m by sunset, light to moderate southwest winds, 1 to 10 mm of precipitation expected, overcast skies. TUESDAY: Freezing level beginning near 1500 m rising to around 1800 m, overcast skies, light to moderate wind generally out of the west, convective snow flurries possible. For more detailed mountain weather information visit avalanche.ca/weather

Avalanche Summary

On Friday numerous size 2.5 isothermal slab avalanches were reported from all aspects including north. A size 3 wet slab was also reported from a solar aspect, likely running on the late February crust. Wet loose activity to size 2.5 was reported to be widespread to size 2.5 on Friday too. Numerous solar releases up to size 2 were reported on Thursday. On Wednesday, loose wet avalanches were reported up to size 2. On Tuesday numerous natural cornice releases resulted in avalanches up to size 3.0 from various aspects in the alpine. On Monday we had reports of several natural cornice falls up to size 2 from various aspects in the alpine. There were also several loose moist or wet avalanches up to size 2 on solar exposed aspects in steep terrain in the late afternoon.

Snowpack Summary

New surface crusts have developed at all elevations on solar aspects and on all but high alpine elevations on shaded aspects. Thin surface crusts may break down early with continued warm temperatures. Approximately 30-50 cm of settled storm snow sits on a melt-freeze crust buried on Mar. 20. The late February persistent weak layer continues to be a concern for wide propagations in isolated terrain, however it may take a large trigger like a cornice fall to initiate an avalanche. Watch for old storm snow releasing as loose wet avalanches on steep solar aspects with continued strong solar radiation and daytime warming this weekend.

Problems

Cornices

Continued high freezing levels and warm temperatures are expected on Sunday, which means that natural cornice failure remains a serious problem. Large cornice fall may trigger buried weak layers resulting in very large avalanches.

Extra caution needed around cornices with current conditions.>Avoid steep slopes below cornices.>

Aspects: North, North East, East, South East, South.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

2 - 5

Loose Wet

Forecast high freezing levels and warm daytime temperatures may break down surface crusts early and result in loose wet avalanches from steep solar aspects. Wet slab avalanches are possible if loose snow propagates on a buried crust.

Be alert to conditions that change with elevation.>Minimize exposure to sun exposed slopes when the solar radiation is strong.>

Aspects: North, North East, East, South East, South.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 4

Persistent Slabs

Continued warm weather may add enough heat to the snowpack to wake-up deeply buried persistent weak layers resulting in very large and destructive avalanches which have the potential to run full path.

Be aware of the potential for large, deep avalanches due to the presence of buried surface hoar.>Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

3 - 6

Valid until: Apr 3rd, 2016 2:00PM