Jasper

Up to 10cm of storm snow has fallen over the last two blustery days and an alpine temperature inversion is expected for Sunday heralding the first signs of relief from the Christmas polar spell. Looks good for the New Year!

An Alpine Temperature inversion has begun to build Saturday as the Jet Stream brings warm air to over-ride the arctic air now established over the area. A spike in the West winds into Monday will help clear out the cold air for good with warm temperatures forecast for next week. Skies will remain clear and winds generally light for the period.

8cm of storm snow now buries isolated pockets of wind slab in ALP areas sitting on an old snow interface of facets, sun crust, wind effect, or surface hoar. 3 crusts extend into the lower limits of the alpine and are sitting dormant in the snowpack, the upper crust is providing mid-pack strength over a weaker, rotted crust and facet crystals

Areas south of Highway 11  in BNP have seen some recent avalanche activity: most notably loose dry avalanches running far in steep terrain as a result of near surface faceting, but a few skier triggered windslabs have been reported as well. These areas have seen considerably more snow over the Dec 18 interface than the JNP forecast area.