Western Wyoming PM Forecast
Issued on Tue January 28, 2020 6:23 PM
SituationToday was overcast with periods of light snow in the morning. During the afternoon as clouds thickened with the oncoming system, snowfall became more consistent and heavier. By 5pm today three to four inches of snow has fallen at the upper elevations of the Tetons and the Southwest Trails areas while one to two inches has fallen on Togwotee Pass. Temperatures at 9000 feet that rose into the mid-twenties by noon today have fallen to near twenty degrees. In the valleys, temperatures rose into the mid-thirties then dropped to below freezing as the storm system began to deliver snow to the lower elevations as well. On summits, winds have backed from the west to the southwest and wind speeds have decreased to fifteen to twenty mile per hour averages.
Although some snow fell between noon yesterday and noon today, a 24 hour period with light accumulations allowed for some strengthening to occur in the upper layers of the snowpack. The top two feet of the snowpack has been reactive the previous few days. Skiers have been triggering soft slabs on density changes formed by varying storm intensities, winds, and temperatures. Given the semi-break today, slabs were less sensitive as the snowpack has better adjusted to these recent loads. No avalanches have been reported for today as of 6pm. The Deep weak layer still exists and although less sensitive, large hard slabs involving that layer can not be ruled out.
Forecast For Wednesday, January 29, 2020Snow is to fall through most of the night. The heaviest snowfall is expected by midnight. By sunrise up to ten inches of snow could have fallen since noon today. Winds are to veer from the southwest to northwest before 8am with averages between ten and twenty miles per hour. Temperature are to drop to the low teens overnight and rise into the mid-twenties during the day.
The general avalanche hazard is expected to be moderate above 7500 feet, although, if stronger winds or more snow is received than expected the hazard could raise to Considerable at the high elevations. New wind slabs with depths to two feet could be found in steep loaded terrain. These slabs could be triggered by riders or skiers, particularly near cliff edges and on convex rollovers. Deep slabs, although slowly becoming more unlikely, could still fail. Initiation of one of the deep hard slabs is likely to take a large trigger such as a falling cornice, or a snowmachine impacting a weak spot on a slope.
Trend For Thursday, January 30, 2020 AND Friday, January 31, 2020Wednesday and Thursday look to be drier and colder. The avalanche danger will decrease during this time.
SPONSORS: Box Y Ranch, Jackson Hole Mountain Resort, Togwotee Mountain Lodge, Brooks Lake Lodge, Wyoming State Trails Program, Bruce Hayse M.D., Chippy's Kitchen and Catering, Grand Targhee Resort, DeFazio Law, Stewart Johnson, CPA, Apex Real Estate and Property Management, Eco Tour Adventures, Grand Teton National Park Foundation, Next Level Riding Clinics, RPK3 Law, Tower 3 Investments, Skinny Skis, Grand Teton Floor & Window Coverings, Snake River Brewing, Jackson Hole Snow Devils, Stio, Teton Gravity Research and Yostmark