JACKSON, Wyo – A cold front will move in Wednesday morning with a short round of snow expected in the Tetons while the valley will see little to no accumulation. A strong storm system will affect the area Friday night and Saturday with heavy snowfall possible. This will initiate an active pattern with additional storms likely through next week.
Recap October 25-31
Last week started active with snow falling on Tuesday (10/25) and Wednesday (10/26) as well as below average temperatures. During that two-day period, the Tetons picked up about 6 inches of snow above 9,000 feet, with 4 inches at 8,000 feet and 1 to 3 inches at the valley floor.
A dry pattern then set in from Thursday (27/10) to Monday (31/10) with a gradual moderation in temperatures. Highs exceeded 50 degrees in the valley on each of the previous four days, but limited daylight hours supported cold lows overnight into the teens.
High temperatures last week ranged from 35°F on October 26 to 55°F on October 31, and low temperatures ranged from 13°F on October 28 to 28°F on October 25.
Forecast from Tuesday (11/1) to Monday (11/7)
The latest wave of sweetness will soon come to an end with a cooler and more active pattern ahead. This week’s first storm will not take a favorable path to produce significant snowfall in the Tetons, but it will bring noticeable changes to the weather.
Prior to Tuesday’s storm, highs will warm to the upper 50s in the valley and strong south/southwesterly winds will also develop in the afternoon.
Early Wednesday morning, a cold front will arrive bringing a short but heavy flurry of snow to the Tetons just before sunrise and during the morning drive. Teton Pass commuters should be prepared for poor driving conditions Wednesday morning as roads will freeze quickly and strong winds could cause reduced visibility.
Most of the snow will fall early in the day with more scattered flurries possible in the afternoon. The Tetons will pick up 2-4 inches of fresh snow. In the valley, precipitation may start briefly as rain or a rain/snow mix early Wednesday before changing to snowfall. However, little to no accumulation is expected in the valley as temperatures will remain above freezing.
Cold and slightly unsettled conditions will prevail Thursday with highs in the mid 30’s. Occasional showers will be possible Thursday but this won’t amount to much, if anything.
Attention then turns to the weekend with a strong storm expected to hit the region Friday night and Saturday. This storm will involve a powerful jet stream accompanied by a plume of significant Pacific moisture – a pattern known as an “atmospheric river” or in more informal terms, a “Pineapple Express”.
The snow could start as early as Friday afternoon, then become heavy Friday evening and Saturday with significant accumulations expected in the Tetons. The valley will see snow accumulation to begin with, but warmer air will arrive on Saturday bringing daytime melting and rain may also mix with the snow.
The chance of snow will persist through Saturday evening with mixed precipitation likely turning to snow in the valley. Another storm is then possible on Sunday and/or Monday with more snow for the Tetons, but confidence is low in terms of timing, temperatures and snow potential in the valley.
Extended Outlook
An active pattern is likely next week with further storms expected frequently mid to late next week. The model seems very favorable to the constitution of an early season snowpack with ski resorts only a few weeks before the opening.
Temperatures will also be colder than average next week with highs generally expected in the 30s in the valley.
Alan Smith, meteorologist
Climatology of the city of Jackson from November 1 to 7:
Medium top: 47
Medium Low: 19
High record: 67 (3 November 1921)
Record low: -14 (4 November 1935)
Precipitation since October 1: 0.97″ (69% of average)
Snowfall in the city since October 1: 4.7″ (estimated)
Snowfall at Rendezvous Bowl since October 1: 29″
Rendezvous Bowl snow depth: ten”
