JACKSON, Wyo. — Get ready for a Labor Day weekend filled with extremes as we start out with near-record heat and high fire danger, and finish the long weekend with a dramatic cool-down and even some snow in the mountains.
The good news is that the big change in the weather won’t occur until Monday afternoon, so backpacking, hiking, climbing, floating and other outdoor plans will all be a “Go” for most of the holiday weekend with prime conditions expected. But, if you have a big excursion planned, you may want to wrap them up by early Monday afternoon.
Friday Outlook:
Currently, high pressure is in control of the pattern over the Western U.S. and as a result, temperatures will heat up into the upper 80s in the valley on Friday afternoon — well above average for early September.
Skies are starting out clear on Friday morning, but we may see some smoke or haze from wildfires in Washington and Idaho arrive from the northwest at times from Friday through Sunday. Fortunately, any smoke we experience this weekend will not be as thick compared to the smoke from the California fires a couple of weeks ago, unless fire activity closer to home changes dramatically in the near-term.
Record Heat Possible on Saturday:
On Saturday, record highs could very well be broken with highs peaking in the low 90s in the Jackson Hole Valley. These temperatures are about 15 degrees above average for this time of year. Fire danger will be on rise as well due to the hot temperatures, low relative humidity and potential for gusty afternoon winds on Saturday and Sunday.
Remember, fire bans are currently in place across the region, so don’t let your guard down just because summer is almost over.
Here are the projected departure from average temperatures for Saturday afternoon:
Another Nice Day on Sunday and Not Quite as Hot:
On Sunday, high pressure will begin to weaken and as a result, we should see temperatures about 5 degrees cooler than Saturday. It will be another great day to get outdoors. Winds could be a bit gusty in the afternoon, so plan accordingly if you’re spending time up high.
Strong Cold Front Arrives on Monday Afternoon:
On Labor Day Monday, we’ll start out quiet and mild in the morning but then the cold front will arrive sometime during the afternoon hours. Strong north/northeast winds will develop behind the front heading into the evening and we will see a dramatic temperature drop as well.
As for precipitation, we will likely see a round of showers develop on Monday afternoon into early evening with the frontal passage with snow levels quickly falling behind the front.
Above 8,000 feet in the Tetons, 1-2 inches of snow will be possible from Monday afternoon through Monday evening and I wouldn’t even rule out a few non-accumulating flakes reaching the valley floor before precipitation ends later in the evening.
Overall, we will only see a glancing blow in terms of precipitation, as winds will quickly be shifting to northeast which favors precipitation in areas along and east of the Continental Divide and less so west of the Divide.
Temperatures will plummet as we dry out later on Monday night and into Tuesday. On Tuesday, highs will only reach the mid 50s in the valley and on Tuesday night lows will fall into the low 20s.
Heavy Snow for the Wind River Range from Monday Afternoon through Tuesday Morning:
Heads up if you’re backpacking the Wind River Range this weekend. From Monday afternoon through Tuesday morning, heavy snow is likely with snow levels falling to trailhead elevations.
The east side of the range could pick up 6-12+ inches of snow during this time, while the west side of the range could pick up 4-8 inches. It would be wise to wrap up your weekend trips by Monday afternoon before this storm rolls in.
Similar snow amounts can be expected for other mountain ranges along and east of the Continental Divide, such as the Absaroka, Beartooth and Bighorn Mountains.
Bottom-line: Most of the weekend is going to be quite nice (if not a bit too hot during the afternoons), so get outside and enjoy before the big changes arrive as the long weekend is coming to a close.
Alan Smith, Meteorologist
Five Day Forecast Charts:
