JACKSON, Wyo. — June is off to an unusually warm start in Jackson Hole, and other than a brief cool snap on Thursday and Friday of this week, the above-average warmth looks to continue for the foreseeable future. Through the first seven days of June, temperatures have been running 9ºF above average in the Jackson Hole Valley.
Record warm low temperatures set last weekend
Last Friday and Saturday, high temperatures rose into the mid 80’s in Jackson but we did not quite reach record levels. On Friday in particular, we were well on our way to challenging the record high of 89, but some cloud cover rolling in from neighboring thunderstorms early in the afternoon put a cap on the warmth.
Even though we didn’t set any record high maximum temperatures, we actually did set two consecutive record high minimum temperatures. You may have noticed this past Friday and Saturday night that your home did not cool off like it normally does, and that’s because overnight temperatures were unseasonably mild.
The low temperature in Jackson only dropped to 54 on Saturday and Sunday mornings, and these values broke daily records for “warm” low temperatures. Average lows during the first week of June are in the mid 30’s, so our morning temperatures were running about 20 degrees above average.
Gusty winds over the weekend likely played a role in overnight temperatures not dropping as much as they usually do. Wind and cloud cover are two key factors that have a moderating effect on temperatures in mountain valleys.
Warm weather through Wednesday, then a cooldown on Thursday
Temperatures are not as warm now compared to late last week, but will remain above average through Wednesday with highs in the upper 70s to low 80s. Average highs at this time of year are in the low 70s. We’ll continue to experience gusty afternoon in winds in response to a trough of low pressure parked along the West Coast.
On Thursday, a rather strong cold front will arrive during the daytime hours. Widespread showers and thunderstorms will develop along and behind the front with Thursday afternoon looking like the wettest period. Overall precipitation amounts do not look overly impressive, but it also looks like our only decent chance of wetting rains for the foreseeable future.
High temperatures on Thursday will likely occur early in the day and by Thursday afternoon temperatures may only be in the 50s in the valley. In addition, the higher elevations will pick up some light snow behind the front on Thursday afternoon with snow levels falling as low as 8,000 feet.
Precipitation will come to an end on Thursday night with clearing skies and freezing temperatures likely in the valley on Friday morning. Highs will rebound nicely into the upper 60s by Friday afternoon under sunny skies.
Heating back up this weekend and next week
We will quickly return to above-average warmth over the weekend and into next week as high pressure builds over the Rockies. By Sunday afternoon, we could be looking at highs in the mid 80s in the valley.
Unfortunately, the extended above-average June warmth combined with little rainfall and pre-existing drought conditions does not bode well for fire season.
Snowpack continues to quickly diminish across the higher elevations as well. In fact, snowpack above 9,000 feet in the Tetons is lower now than it has been on any previous June 7 since at least 2007. As a result, higher elevation hiking trails are melting out a couple of weeks earlier than usual.
Alan Smith, Meteorologist
