JACKSON, Wyo. — The first major cold front of the fall season arrived on Sunday, along with the first widespread snowfall for the mountains. Snowfall observations are limited this early in the season, but the Raymer Plot at Jackson Hole Mountain Resort (elevation 9,360 feet) showed 3 inches of snow on the ground as of Monday morning.
Check out the scene over the Tetons from early Monday morning:
A leading-edge disturbance on Saturday afternoon resulted in a couple of rounds of showers and thunderstorms along with strong winds, followed by more widespread precipitation, cooler temperatures and lower snow levels on Sunday and Sunday night.
Precipitation totals on Saturday and Sunday ranged from 0.25-0.6 inches in the Jackson Hole Valley with estimated totals (due to a lack of weather station reporting) of a half-inch to an inch over the Tetons. The Alta weather station on the west side of the Tetons recorded an impressive 0.75 inches of precipitation.
The recent moisture along with cooler temperatures heading into the fall season likely means that our potential for significant wildfires is over for the year in Northwest Wyoming. Fire season does persist for a bit longer across the drier regions of Southern and Central Wyoming (east of the Continental Divide) as well as the Snake River Basin in Idaho.
The good news for hikers and climbers is that this first cold front and snowfall was just a blip. Not only was snowfall light overall (by most indications, just a few inches or so up high), but now we have an extended stretch of warm and sunny weather ahead.
The snow that accumulated in the mountains will quickly melt, except perhaps on high elevation, shaded aspects on the highest peaks.
Check out the images of the snow covering the Tetons on Monday morning (which was beautiful for sure) from the Spring Creek Ranch webcam:
Â
Now, check out these same views as of early Tuesday afternoon. The snow is already melting quickly, at least on the more sun-exposed aspects:
Â
A ridge of high pressure will build over the Western U.S. over the coming days, resulting in an extended stretch of sunny skies and warmer temperatures for Jackson Hole through early next week.
After a high of only 51 in Jackson on Monday, highs will warm up into the mid-60s under mostly sunny skies on Tuesday afternoon.
On Wednesday, we’ll see a more noticeable warm-up after a chilly start to the morning with highs reaching the low 70s in the valley. Winds will also become breezy in the afternoon out of the southwest ahead of an approaching weak disturbance.
A weak cold front will arrive on Thursday morning, but no precipitation is expected with partly cloudy skies early giving way to mostly sunny skies in the afternoon. Daytime temperatures will be slightly cooler behind the front with highs in the upper 60s in the valley.
Friday through Monday will be sunny and beautiful and temperatures will trend warmer with highs in the 70s expected each day in the valley. Winds should also be relatively light and out of the southwest during this period.
Keep in mind that just because our afternoon temperatures will be warmer, nights and mornings will still be very chilly given that we’re in late September. Valley low temperatures will be well below freezing most mornings over the next week.
Around the middle of next week, we could eventually see a disturbance or two arrive from the Pacific, resulting in a chance of some showers across the area. At this time, temperatures look to remain mild with snow levels remaining high as a result. However, this outlook could always change moving forward as we are still at least a week away.
Another thing to keep an eye on next week is the possible arrival of light smoke/haze from wildfire activity in California’s Southern Sierra Nevada Range. This would be the result of a more persistent southwest wind pattern across the Western U.S. If we do see any of this smoke, hopefully, it will only be minor and short-lived.
Alan Smith, Meteorologist
