Avalanche Forecast
Issued: Feb 13th, 2015 8:28AM
The alpine rating is Storm Slabs, Persistent Slabs and Wet Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Poor - Due to the quality of field observations
Weather Forecast
A ridge will build over the weekend signaling an end to the deluge. Rain will continue overnight Friday with coastal regions receiving up to 10mm of rain and snow although this is expected to taper off rapidly further inland. The freezing level is forecast to drop to 1000m on Saturday with moderate westerly winds. Isolated showers may persist into Sunday although a clearing trend is expected as the winds become northwesterly, bringing scattered clouds and a freezing level of 750m. The region should be mainly dry by Monday when broken skies, light south west winds, and a freezing level of 1500m are expected.
Avalanche Summary
Warm temperatures, wind, snow and rain drove a natural avalanche cycle that started on Wednesday. Since then we have received reports of numerous natural and explosive controlled slab avalanches up to size 3 on all aspects above 1000m with widespread loose wet avalanche activity bellow . I am unsure if all of these avalanche were contained to the storm snow or if some may have released on one of the deeper week layers.
Snowpack Summary
Between 20 to 70 mm of precipitation in the form of new snow and/or rain had fallen through the storm as of Friday evening. In many places this sits on a thin layer of surface hoar that formed in the brief lull between systems on Febuary 10th. The freezing level rose to 1500m in the southwest corner of the region on Friday with cooler temperatures recorded further inland and to the north. Predominantly strong southwest winds have loaded lee features in the alpine and at treeline. Before this storm the late-January crust could be found down between 60 to 150cm in the south of the region and about half this depth in the north. This crust may have surface hoar on it. The mid-January rain crust and/or surface hoar layer is down over 160cm in the south and has generally become inactive. The November crust/facet combo near the bottom of the snowpack is still on my radar as a potential problem layer in the far north of the region.
Problems
Storm Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Wet Slabs
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Feb 14th, 2015 2:00PM