Avalanche Forecast
Issued: Apr 21st, 2012 4:00PM
The alpine rating is Loose Wet, Wet Slabs and Wind Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Fair - Due to limited field observations for the entire period
Weather Forecast
A weak Pacific front is expected to approach the Northwest from the south on Sunday. Light precipitation is expected during the day with moderate southeast winds and freezing levels rising to about 1500 metres. A ridge of high pressure is expected to develop on Monday bringing mostly clear skies and drier conditions with light winds.
Avalanche Summary
Spring conditions exist in the region. Exposure to the sun, warm temperatures, and periods of rain are the most likely factors to influence the avalanche danger. If the temperatures go below freezing overnight, strong crusts should develop that are likely to hold the snowpack together. If the sun shines for a few hours, the crusts may break down quickly and moist surface snow avalanches may start running naturally. Continued warming from more sun, rain, or no overnight freeze, may cause surface avalanches to step down and trigger deeper wet slab avalanches. Prolonged warming may cause very deep releases on weak layers that were deposited early in the season, or on depth hoar that developed during the winter. It is important to monitor the temperature and the freezing levels as they may change rapidly from day to day.
Snowpack Summary
As we transition into spring, the surface layers have a great deal of influence on the snowpack. When there is a solid re-frozen surface crust, travel is fast and easy, and the snowpack is held together by the surface cap. Any deeper persistent weak layers are unlikely to fail until the surface cap breaks down from daytime heating. When there is no crust, surface layers and any deeper weak layers may fail, depending on the amount of heat and the triggering force that is applied. If it cools off and snows, new snow and wind slabs may not bond well to the hard spring crusts. For more information on Spring Conditions and ways to mitigate risk, please visit the new Forecasters' Blog Post.
Problems
Loose Wet
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Wet Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Wind Slabs
Aspects: North, North East, East.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Apr 22nd, 2012 9:00AM