Weak Layer

Comments:

Name: Early December Crust

Author: DG

Zones: OLY, HD, WN, WC, WS, EN, EC, ES, STV, SNQ Comments:

20211209: DG: This layer describes the basal MF/IF that exist widely across the forecast region, particularly near and above treeline. This layer typically extends to above ridgeline in most areas. Some question exist about this layer in the EN zone. The basal MF/IF were buried on 12/2 by light snowfall in most locations (date verified at Baker and Paradise).

20211214: JH: This layer was buried on Dec 4th in the Stevens and most of the EN zones. Tests at Stevens have been variable w both sudden and resistant planar tests results. At the top of WA Pass near and above TL on Nrly aspects, the layer is 70-90cm above the ground w other MF/ ice layers below it. Results here have also been variable, though Nrly aspects have produced some surprisingly sudden and propagating tests.

20211219: Name officially changed from “late November” to “early December.” 12/18 cycle reveals no known avalanches on this interface. Observers in E North zone continue to get tests indicating propagation in CT and ECT. All zones where it is a consideration (EN, SP, EC, ES) are calling it the “early December crust.”