Mid-week rain will be followed by beautiful weather this weekend
JACKSON, Wyoming – We are moving into an early fall weather pattern across northwest Wyoming as warm days and cool nights become the norm. Rain and thunderstorms on Wednesday will give way to dry and sunny conditions by the end of the week.
Since Labor Day, “comfortable” and “a little unsettled” would be the best way to describe the weather pattern. The weather hasn’t been completely dry and cloudless, but we’ve certainly seen less rain recently than in previous weeks.
Frequent minor disturbances have produced cloud accumulation and scattered showers most days, but very little precipitation has been measured over the past few days with most areas recording anywhere from a trace to a few hundredths of an inch.
Temperatures were nearly perfect with highs in the 70s and lows in the 30s. We still haven’t seen our first freeze in Jackson yet this year. The average first freeze is in late August, so we are a few weeks behind schedule.
At the same time, it’s becoming increasingly likely that we’ve already seen our 80-degree day of the year already. In fact, we didn’t get to 80 degrees Fahrenheit at all in September, which is unusual if this continues.
So far, temperatures are 1.7 degrees Fahrenheit above normal for September overall. However, as in August, high temperatures are slightly below normal while low temperatures are above normal.
Upcoming weather pattern
A low pressure system moves through the central Rockies on Wednesday, bringing unstable weather conditions. We saw a few rounds of rain move in Wednesday morning, while the early afternoon saw more sunshine.
Rain and thunderstorms are expected to increase heading into Wednesday afternoon and Wednesday evening, as a cold front approaches.
Snow levels will be fairly high through Wednesday evening, generally between 11,000 and 12,500 feet.
Thursday, we’ll start out dry with a slight chance of showers in Jackson Hole, while there will be a better chance of showers east of the Continental Divide in the Wind River and Absaroka Range.
High pressure will build over the region from Friday to Sunday, leading to mostly sunny skies and dry conditions. It sounds like the perfect weekend to be outdoors, so enjoy!
High temperatures will be in the upper 60s on Wednesday and Thursday, before rising to the mid-70s Friday through Sunday. As the humidity begins to drop, we will experience cold nights and mornings, and perhaps we will finally see our first freeze in Jackson.
Next week, the pattern will become more disturbed as a low pressure system is expected to move into the western United States around September 19-20 (approximately).
The path of this system and associated impacts around Jackson Hole are uncertain at this time. But at the very least, there’s a chance we’ll see showers and cooler temperatures around September 19-20, and perhaps some snow at higher elevations.
Below is a 7-day rainfall forecast, which mainly represents the rainfall expected today (September 13) and early next week (September 19-20).
Following a likely weather system from September 19-20, longer-range models suggest we could start to dry out and warm again next weekend (roughly September 21-24).
After that, there are some hints that the pattern could become unstable again heading into the week of September 25, but confidence is low so far.
Alan Smith, meteorologist