JACKSON, Wyo. – A dry pattern will continue through the weekend and into early next week with highs in the 80s. Occasional isolated “dry” thunderstorms are possible locally, with better rain chances north and east of the Jackson Hole area.
Recent Weather
An early summer surge of monsoonal moisture from the south contributed to daily rounds of showers and thunderstorms from July 1 to 4 with variable rainfall totals.
Jackson Hole Mountain Resort recorded the heaviest rainfall totals across the region with 4-day totals ranging from 0.8 to 1.2 inches. Note that there are no rain gauges located in the Tetons north of JHMR.
In the Jackson Hole Valley, rainfall amounts ranged from 0.25 to 0.75 inches in the southern valley with the highest totals around Wilson and Teton Village, while the town of Jackson received 0.38 inches of rain over this 4-day stretch.
July is Jackson’s driest month on average. The town of Jackson only averages 0.79 inches of rain for the month as a whole, so 0.38 inches in 4 days isn’t bad for this time of year. But of course, it would be nice if we could pick up some more rain later this month after a well below normal June.
The northern Jackson Hole Valley (north of the airport) and Teton Valley did not fare nearly as well, with rainfall amounts of only 0.1 to 0.2 inches in most areas. To the south, heavier rainfall amounts were recorded across Lincoln and Sublette Counties, especially on Friday, July 4.
Since July 4, we have entered a much drier weather pattern, and temperatures have also warmed back up following a cooler spell over the holiday weekend.
Last Friday, the high temperature in Jackson was only 71º, which is about 10 degrees below average, but starting on Monday, warmer air returned, and we have seen highs well into the 80s this week. In fact, on Wednesday afternoon, we just hit 90ºF in Jackson for the first time this year.
Upcoming Weather Pattern
A warm and dry pattern is expected in Jackson Hole over the next week, though temperatures will fluctuate a bit, and we will see some occasional isolated thunderstorm chances sneak into the picture.
On Wednesday night and Thursday morning, a weak cold front will move through and there is a small chance that we could see some nighttime and early morning thunderstorm activity. Something to keep in mind if you have early morning climbing plans.
On Thursday, temperatures will be cooler behind the front with highs in the low 80s, which is still right around average for this time of year.
On Friday, another cold front will move through with just enough moisture for a chance of isolated afternoon thunderstorms. Any storms that develop will likely be of the “dry” variety, producing brief light rain and strong wind gusts.
Thunderstorm chances will be higher east of Jackson Hole across the Absaroka, Beartooth, and Bighorn Ranges on Friday. Yellowstone will also see a comparatively higher chance of storms versus the Tetons.
On Saturday and Sunday, dry and sunny conditions are expected with highs reaching the mid to upper 80s. Thunderstorms are unlikely on either day.
Next week, we will likely be just on the edge of the moisture once again as a low pressure trough is expected to pass north and east of our area around mid-week. This could result in thunderstorms with the potential for soaking rains near the Montana border and east of the Continental Divide, including the Winds, Absarokas, and Beartooths.
However, in Jackson Hole and the Tetons, we will probably be looking at an isolated thunderstorm setup at best around mid-week (July 15-17-ish) with any storms producing brief light rain.
The 7-day rainfall projection from the European Ensemble Model highlights this setup well, with very little rain for the Tetons, while areas just north and east of our area are expected to see heavier rainfall.
Looking ahead, above-normal temperatures are expected from July 17-23, with temperatures possibly starting cooler around this time, thanks to a cold front around the middle of next week, before trending warmer after.
For perspective, the average high in Jackson in July is 83ºF.
The North American Monsoon is expected to strengthen over the Southwest U.S. between July 17-23, where wet anomalies are projected. We may eventually see some of this moisture sneak into our area from the south, which could lead to an increase in thunderstorm potential.
Alan Smith, Meteorologist
