Avalanche Forecast
Issued: Mar 7th, 2020 8:00AM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Persistent Slabs.
percy woods,
Parks Canada
The buried February 22 surface hoar layer (weak layer) is lurking at a depth within range of human triggering. Conservative use of terrain is advised.
Summary
Weather Forecast
Flurries today with accumulation around 8 cm. Alpine temperature a High -4 C with ridge wind southwest 10-30 km/h. The freezing level should rise to 1600m. A trace of snow overnight with cooling temperatures. Sunday-Monday expect a mix of sun and cloud, SW winds in the moderate range and ridgeline temperatures in the -10C--14C range.
Snowpack Summary
15cm+/- of storm snow with light winds covers recently formed windslabs in open terrain features at all elevations. Previous wind effect appears to be highly variable. Below these slabs, the Feb 22nd persistent weak layer is now buried down 50-80cm, and consists of 3-7mm surface hoar on all aspects up to 2450m, and a crust on solar aspects.
Avalanche Summary
Glacier National Park VS staff responded to a InReach call for a sled triggered size 2.5 slide that occurred inside the E boundary of Glacier National Park in the Bald Hills. Evidence indicated 2 sleds were involved and the group self extricated. Five natural avalanches to size 1.5 off Mt MacDonald east of the pass in the highway corridor.
Confidence
Problems
Wind Slabs
Storm snow is hiding recently formed windslabs. Expect underlying windslab in open terrain features on all aspects in the Alpine and exposed areas of TL and BTL. If triggered these wind slabs have the potential to step down to the Feb 22nd SH layer.
- Be aware of the potential for wide propagations due to the presence of hard windslabs.
- If triggered the windslabs may step down to the Feb 22 SH layer with potential for large avalanches.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
The Feb 22 Surface Hoar layer is down 100cm+/- at treeline in the W end of the park and 50-80cm in the E. It is a likely depth for skier triggering, especially in shallower snow pack areas. Steep solar aspects harbor a crust under the SH layer.
- Be aware of the potential for wide propagations.
- Avoid steep convexities or areas with a thin or variable snowpack.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Mar 8th, 2020 9:00AM
