The combination of recent snow, wind, and buried weak layers make human triggered avalanches possible today. Steep and rocky areas that have been wind affected on north through east through south aspects are the most likely areas to trigger a slab. Monitor the wind direction and pay attention to signs of instability such as cracking within drifted snow or audible collapsing of the snowpack.
Wind slabs (both soft and hard) are possible at the upper elevations today, with depths around 12 inches.
Up to 8 inches of snow has fallen at the upper elevations in the Togwotee zone over the last 4 days. This snow has largely been medium density and is available for transport. Monitor the wind direction and look for blowing and drifting snow.
Weak, sugary snow is buried 1-3 feet deep below the surface of the snow. These layers formed from cold, dry periods that occured in November and early December and are widespread. Avoid steep and rocky areas that are wind effected where triggering a slab is more likely.
West and North aspect now have a thick layer of surface hoar all the way up to 10k in the Togwotee Zone.
(1/1/2023) R3D2 on Angle mtn. Photo: Andrew Newman
Weather Synopsis
Currently western Wyoming is being affected by a shortwave trough that has been kicked out in front of a larger low pressure system. This larger system is a broad trough with a low currently centered near the mouth of the Columbia River. Moist SW flow will affect the forecast area today with 1-2 inches of additional snowfall and gusty SW winds.
A deep trough that eventually closed off north of the Texas Panhandle dropped 12-15 inches of snow with over an inch of SWE in the Tetons and the Greys zones on January 11/12. Togwotee received closer to 6-8 inches of snow with this system.
Prior to that WSW flow with imbedded Pacific moisture impacted the forecast area with 3-7 inches of snow and breezy conditions on January 9/10.
Recent Avalanches
The most recent natural avalanche cycle followed on the heels of tropical moisture in a SW-W flow that hit Togwotee from December 27- January 1. No human triggered avalanches have been reported recently.
Snowpack Summary
Current snow surfaces are composed of medium to high density snow that has settled from the January 10/11 storm and suface hoar/near surface facets. In wind affected areas the surface of the snow has turned into upside down wind slabs.
Snow depths are approaching 1-1.5 meters at upper elevations in the Togwotee area. The top half of the snow pack is composed of new, decomposing, and wind packed snow. The bottom half of the snowpack is composed of crusts and advanced facets that are in excess of 2mm in some locations. All of the snow from November and October has faceted, with the October snow taking on the form of depth hoar.
