South Rockies

Poor - Due to limited field observations

Mostly sunny conditions are expected to prevail on Monday. The inversion forecast for the rest of the interior is expected to be pretty weak in the south. There may still be a short period of above freezing temperatures in the alpine on Monday. Gusty southwest winds are forecast for Tuesday as a cold front moves quickly through the region. Moderate precipitation is expected for the East slope of the Rockies on Wednesday. Freezing levels should be down to valley bottoms on Tuesday and Wednesday.

We have a report of a large avalanche (size 3.0) triggered by a snowmobiler in the Mt. Corbin area on Saturday. Sounds like some snow stiffened by the wind released down deep on the weak facets. We will try to get more information up tomorrow. Check-out our CAC Field Team`s observations from the Harvey Pass area in our South Rockies discussion forum.If you have any observations from the field, please drop us an email: [email protected].

Snowfall accumulations have not been sufficient to create an avalanche problem below treeline where the snowpack sits at about 30-60cms. Regardless, slopes at higher elevations have been large enough to run down to terrain located well below treeline. In the alpine, and at treeline the snowpack depth generally sits anywhere from 80-120cm with deposits of up to 400 cms on wind-loaded features.Reports suggest that strong to extreme winds in a few parts of the region have stripped west aspects of snow creating wind slabs on lee and cross-loaded aspects in the alpine and at treeline. Many of these new windslabs could be sitting on the reactive October rain crust located a few centimetres above the ground. This rain crust may have weak, overlying facets and is widespread in the alpine and isolated in its distribution at treeline. This is a classic low probability-high consequence scenario where the snow may have been gaining strength, but the consequence of an full-depth avalanche could still be disastrous. Its worth noting that while the crust-facet combo has been an issue in some areas, it seems to be non-existent in others parts of the region. The 'take home' message is that the region as a whole is data-sparse and extremely variable in terms of snowpack structure. When heading into avalanche terrain, do so gradually and take the time to gather terrain-specific information. Check-out our CAC Field Team`s observations from the Harvey Pass area in our South Rockies discussion forum. Your reports from the field are also highly valued. Any observations can be sent to: [email protected]