Avalanche Forecast
Issued: Mar 25th, 2018 4:29PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs.
jmcbride,
Avalanche Canada
A significant storm is expected Sunday night, into Tuesday. Although snowfall amounts are uncertain, expect to find touchy storm slabs at all elevations. These slabs may be surprising deep and reactive on leeward slopes at treeline and above.
Summary
Confidence
Moderate - Intensity of incoming weather systems is uncertain
Weather Forecast
Snowfall amounts are uncertain for Monday/Tuesday's storm event, but significant snowfall is expected for the region with rising freezing levels.TONIGHT: Snow. Accumulation 15-25 cm. Ridge wind moderate to strong, southwest. Temperature at treeline -3. Freezing level 600 m.MONDAY: Snow. Accumulation 20-30 cm. Ridge wind moderate to strong, southwest. Temperature at treeline near -2. Freezing level 1000 m.TUESDAY: Snow changing to rain. Precipitation 10 -30 mm. Ridge wind moderate, west. Temperature at treeline +2. Freezing level rising to 1600 m.WEDNESDAY: Cloudy with sunny periods. Ridge wind light, northwest. Temperature at treeline near 0. Freezing level 1500 m.
Avalanche Summary
Ski cutting on the North Shore mountains on Saturday produced small (size 1) releases within the recent storm snow about 10 cm deep.Thursday morning ski cutting work on the North Shore mountains produced loose, dry storm snow releases (size 1) above 1000 m and loose, wet size 1 releases below 1000 m.There have been no reports from the northern part of the region around Squamish, however it's likely that a natural avalanche cycle occurred in high alpine terrain with the recent storm.
Snowpack Summary
About 25-35 cm of snow has fallen on the North Shore mountains since Thursday with light to moderate east/southeast wind. The warm to cold nature of the storm has allowed this new snow to bond well to the old surface up to treeline. Alpine areas around Squamish saw more snow (40-60 cm) and wind. In these areas the new snow is likely sitting on a mixture of weak grains including a crust on solar aspects and potentially facets/surface hoar on polar aspects. Below the recent storm snow the snowpack is generally well settled and strong.
Problems
Storm Slabs
Significant snow and moderate to strong southwest winds will likely form reactive storm slabs. These may be surprisingly deep and touchy in wind loaded areas near treeline and in the alpine.
Watch for whumpfing, shooting cracks and recent avalanches which indicate unstable storm slabs.Avoid avalanche terrain during periods of heavy loading from new snow, wind, or rain.Give cornices a wide berth when travelling on or below ridges.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Mar 26th, 2018 2:00PM
