Friday brought cooling following Thursday's wet, warm storm.
With the high freezing levels, accumulations at treeline were modest. Expect a very different picture in the alpine.
While fresh slabs can be found in specific features at treeline, widespread and much more developed slabs exist in the alpine.
Fresh slab development has occurred as a result of the South through West winds that arrived with the storm snow. Widespread, 20-40 cm thick slabs can be expected in the alpine. Slabs at treeline are thinner and more specific in their distribution due to the storm's high freezing levels.
Visibility was poor Thursday and human activity was limited.
A flight to Bow Hut Friday, again in poor visibility, found many slabs out in alpine lee fans 20-40cms thick that were likely triggered from above and that propagated 20-30m to sz 1.5. Lake Louise triggered 3 sz 1.5 slabs near ridge top averaging 15cm deep and saw a single natural slab low on the slopes of the National Geographics.
Sunshine had no results to ski cutting at treeline elevations.
Up to 50mm of rain has been recorded in the past 36 hrs in Kootenay NP, with amounts around 20mm north of this. With freezing levels for the period near 2200m, only about 10-20cm of snow is expected to have accumulated at treeline elevations. In the alpine, more snow is expected to have arrived. Moderate to strong S-W winds have developed fresh wind slabs. Snow pack depths taper rapidly below 1800m. The wet snowpack at low elevations is in the process of re-freezing Friday.
The winds are now out to the West and expected to continue in the moderate to strong range through Saturday. Temperatures at treeline will drop to -10C overnight Friday and a few cm of snow is possible into the morning hours as treeline temps recover to around -5C.
