Weak Layer

Weak Layer Information

Layer Burial Date:
November 22, 2022
Layer Grain Type (Primary):
FC - Faceted Crystals
Layer Grain Type (Secondary):
SH -Surface Hoar
Comments:

Names: 11/22, or mid November Facets

11/25: Long dry spell in mid November ended 11/22 with a strong front. Snow levels were high (5.5-6K) on the west side of the central crest, down to valley bottoms on E Side Valleys. Small cycle observed on 11/23 N slopes Lichtenberg, all slides below 5k.

Fair to large amount of uncertainty with current distribution: Rain and warm temps on 11/25 may have eliminated this problem in many areas, but uncertainty exists at Snoqualmie, Stevens, EC, EN and WN/WC above 5.5-6.k. Perhaps pockets in low, sheltered locations near Xtal. MP

 

20221212; Blewett Pass/Tronson Meadows, well developed 2-3mm FC; SC results in stability tests (CT3 SC, ETP21 SC): KW

Media

The thin snowpack at 4700ft (North aspect) on Blewett Pass consists of moist, weak, rounding facets below a layer of moist to wet decomposing fragments and rounds.
Profile from a north facing slope at 4,800ft on the north side of Lichtenberg.
These natural slabs appeared to have ran during the tail end of the last storm (11/22). They ran on a layer of weak, sugary facets and a thin crust buried just beneath the recent storm snow. Similar activity was a common sight on the north slopes of Lichtenberg.

Weak Layer Observations

Professional Field Reports:
Dec 17, 2022 - Glacier Peak Wilderness — Trinity Area
Dec 8, 2022 - Hairpin Valley
Dec 1, 2022 - North side Cashmere, Icicle Creek
Avalanche Occurrences:
Jan 18, 2023 - Blue Lake Peak
Dec 14, 2022 - Finley Canyon
Dec 10, 2022 - Kangaroo Ridge