Avalanche Forecast
Issued: Mar 12th, 2013 11:04AM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs.
slemieux,
Avalanche Canada
Warm temperatures and heavy precipitation are increasing the avalanche danger in the days to come. Good time to avoid avalanche terrain or to make very conservative terrain choices out there.
Summary
Confidence
Fair - Forecast snowfall amounts are uncertain for the entire period
Weather Forecast
Tuesday night and Wednesday: The strong Westerly flow bringing significant precipitation amounts into the interior should taper off a little tonight but should keep delivering moisture until Friday. Amounts could be around 20 mm in water equivalent till tomorrow evening. with winds blowing strong from the W. Freezing levels are expected to rise to close to 2000 m. during the day and stay high until Friday.Thursday: Similar amount of precipitation and freezing level is expected for Thursday with strong winds switching from the SW.Friday: The Westerly flow is forecasted to weaken and precipitation to taper off. Freezing levels and wind speeds should also start to drop.
Avalanche Summary
More and larger avalanches are expected with the forecasted warm and heavy precipitation in the days to come.
Snowpack Summary
Currently, 10 cm of new snow overlies a variety of surfaces; hard wind slabs lee of N, SW and W winds in alpine and treeline features, a well developed surface hoar in shaded areas above 1700 m., a melt-freeze crust below that elevation and a 3 cm sun crust on solar aspects at all elevations. The forecasted precipitation and warm temperatures will add a good load to the snowpack (could be another 20 mm in water equivalent till tomorrow night). The variety of surfaces described earlier will most likely be reactive to this new load and create a good failure plane for avalanches to slide on. With freezing levels rising again tomorrow, the new dryer snow layer at the upper below treeline and treeline elevation band (between ~1500 m. and ~2000 m.). could get soaked and create wetslabs and loose wet avalanches.
Problems
Storm Slabs
Heavy precipitation and warm temperatures are expected in the days to come creating new storm slabs, new wind slabs lee of strong SW winds in the alpine and treeline and adding significant load on the underlying layers.
Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.>Avoid exposure to overhead avalanche terrain, as large avalanches may reach runout zones.>
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Mar 13th, 2013 2:00PM
