Avalanche Forecast
Issued: Mar 9th, 2017 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Persistent Slabs.
grant statham,
Avalanche Canada
We expect the hazard to rise overnight Thursday, with new snow, strong wind and a sharp rise in temperature forecast. This may trigger a natural avalanche cycle on Friday. Ice climbers remember there is WAY more snow overhead at higher elevations.
Summary
Weather Forecast
A westerly flow brings another system across the region starting Thursday evening and running until Saturday morning. Friday will be a stormy day; expect another 10 cm at treeline with temperatures rising 10-15 degrees through the day. Winds will also rise, reaching SW 50-75 km/hr at 3000m throughout Friday morning.
Snowpack Summary
60-70cm of storm snow over the past week is surprisingly reactive. With the addition of more snow, increasing wind and rising temperature on Friday, the upper meter of the snowpack will continue to produce avalanches. Expect fresh windslab formation in avalanche paths on Friday with plenty of volume for large avalanches to run long distances.
Avalanche Summary
Large avalanches are occurring daily. Thursday's avalanche control produced size 3 avalanches on Mt Field running over the ice climb Silk Tassel. On Hwy93N, we triggered a size 3 on Mt Hector and a size 2.5 on Dolomite Peak as well as observed fresh natural avalanche activity. Heads up if you're ice climbing in Field - naturals may run on Friday.
Confidence
Problems
Wind Slabs
60cm of dry snow from the past week is being blown into cohesive windslabs at higher elevations. Expect these to react easily to triggers, and keep your distance from avalanche starting zones. We have seen long propagations up to 400m this past week.
- Be aware of the potential for wide propagations.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
Several buried weak layers in the middle of the snowpack are gaining strength over time as they become bridged, especially in the deeper areas closer to the Wapta. Dig down to see if they are present on your line, and how they are reacting.
- Dig down to find and test weak layers before committing to a line.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 10th, 2017 4:00PM
