JACKSON, Wyo. – Jackson Hole has been in a rollercoaster weather pattern lately. A significant storm cycle produced 21-33 inches of snow in the Tetons from December 1-4. An unseasonably warm airmass has taken hold since this storm ended, but another storm with colder temperatures is on track for late this week.
December 1-4 Storm Cycle Brings Much-Needed Snow to the Tetons
Following a lackluster November, a series of storms arrived during the first few days of December with deep snow totals adding up in the Tetons.
During these four days, snow totals across the higher elevations included 33 inches at Grand Targhee, 30 inches at Jackson Hole’s upper mountain, 25 inches at Jackson Hole’s mid-mountain, 21 inches at Surprise Meadow in Grand Teton National Park, and 13 inches at Togwotee Pass.
Across the lower elevations, snow totals included 10.2 inches at Moran/Jackson Lake, 10 inches at Snow King, 7 inches in Teton Village, and 5.7 inches in the town of Jackson.
Snowfall was “upside down” in this storm cycle, meaning that snowfall started out dry and powdery early in the cycle before turning wet and dense toward the end of the cycle as temperatures increased.
December 4-6 Warm Spell
The December 1-4 storm cycle was immediately followed by unseasonable warmth. By the time the storm was winding down on Monday morning, snow had turned to light rain in the Jackson Hole Valley with temperatures in the upper 30s.
High temperatures reached the mid 40s in the valley on Monday afternoon and did not freeze on Monday night with lows in the upper 30s. The high in Jackson then hit 51ºF on Tuesday, which is just shy of record levels for early December.
The warmth has impacted the higher elevations as well with temperatures reaching the upper 30s at 8,000-9,000 feet and low 30s at 10,000 feet.
The November dry spell which was followed by a deep “upside down” storm cycle, which was then followed by a significant warm snap have all wreaked havoc on snowpack stability and avalanche conditions. Be sure to check out the Bridger-Teton Avalanche Center Forecast for more info.
Snowpack Update
Snowpack (the amount of snow on the ground) has improved following the early December storm cycle but is still below average for this time of year.
Currently, snow depth values are 80-90% of average across the higher elevations in the Tetons above 9,000 feet and 60-75% of average across the mid to lower elevations of the Tetons (8,000 feet and below).
Despite the recent warm spell, Jackson Hole and Grand Targhee have started to open up more lifts and terrain following the last storm cycle. Snow King is also scheduled to open for the season this Friday, December 8.
Snow and Colder Temperatures Return on Thursday
Wednesday will be our last unseasonably warm day, then a storm will arrive early Thursday morning with a cold front moving through at the leading edge. Heavy snow and strong winds will impact the commute on Thursday morning with snow continuing throughout the day.
Additional snow showers are also expected from Thursday night through Friday, favoring the higher terrain, with snow becoming drier and more powdery over time. Colder temperatures will also take hold on Thursday night and Friday morning, which may result in icy conditions on the roads as wet areas on pavement freeze up.
Total snowfall from early Thursday morning through Friday evening will range from 9-20 inches across the higher elevations of the Tetons and 2-7 inches in the Jackson Hole Valley with the higher end of this range favoring areas west of the Snake River and north of the airport.
Following this storm, we should see a brief break on Saturday then a weaker storm will move through on Sunday with a refresh of light to moderate snow expected. Temperatures will be seasonally cold through the weekend with highs ranging from the mid 20s to low 30s in the valley.
Here is a snowfall projection over the next seven days from multiple simulations of the European weather model. The storm track will favor the Pacific Northwest and into the Northern and Central Rockies.
After Sunday’s storm, it looks like we are going to head into a dry spell during the week of December 11-17. Temperatures will start out cold earlier in the week then will gradually rise in the mountains later in the week. We may also see inversions set up later next week, which would result in colder temperatures in the valley than in the mountains.
Alan Smith, Meteorologist
