(Western Wyoming) – The Bridger-Teton Avalanche Center issued the following advisory on Thursday, March 4th at 6:37 pm.
Know before you go – the latest information and condition updates can be found here.
Skies were clear again today with a few distant clouds visible to the south of the region this morning. Temperature inversions were slightly stronger with high elevations starting off in the mid-twenties which was about 5 degrees warmer than yesterday morning. High temperatures reached into the thirties today even on summits, while mountain locations rose to the mid-thirties in shaded terrain and into the low forties in sunlit basins. Winds were calm this morning and picked up to speeds of ten to twenty miles per hour this afternoon from the west-northwest.
Each cycle of above freezing days and cold nights is forming stronger crusts on south facing terrain. Flatter terrain and shaded terrain remains crust free and is settled powder. Near surface faceting is occurring during the nights where loose snow lies and in north facing terrain surface hoar can be found at a variety of elevations. It is transitional point of the winter. For all of February significant and consistent snowfall was resulting in avalanches involving both constantly evolving surface instabilities as well as deeply buried weak layers. As the snowpack is settling and adjusting during these melt-freeze cycles, it continues to gain strength overall although warm afternoons continue to provide periods of increased hazard. Today, in Snake River Canyon, a fairly small slide naturally released on a steep man-made terrain feature and covered one lane of the highway.
FORECAST FOR: Friday, March 05, 2021
Another day of high pressure and clear skies is forecast for tomorrow. Expect temperature inversions again in the morning that are to start just a few degrees warmer than today. Highs temperatures are also forecast to be slightly warmer. Winds are to be light and variable.
In the Tetons the avalanche danger will be Low in the morning and Moderate in the afternoon. As temperatures soften and weaken the upper portion of the snowpack, the possibility of human triggered slab avalanches will develop, particularly in very steep and extreme terrain. Hazards associated with warm sunny days will also increase, including wet slides and a possibility of cornice failure.
In the Southwest Trails area, where weak layers remain more of a problem, the danger will increase from Moderate to Considerable. Increasing temperatures will weaken the snowpack, allowing the possibility for human triggered slab avalanches that could be small in isolated terrain features or very large and destructive in steep avalanche paths. Wet slides will also become possible especially in areas where the snowpack is very steep and shallow.
On Togwotee Pass, the snowpack is generally weaker with a significant portion of the lower snowpack containing preserved weak, sugary snow. Human triggered avalanches could occur. These could fail to the ground, especially in the afternoon when the warmest temperatures of the week are forecast. The danger rating there will be Considerable above 8000 feet and Moderate below that elevation.