JACKSON, Wyo. — Summer is starting fast in Jackson Hole this year. After a beautiful and sunny Memorial Day weekend with comfortable temperatures, the first week of June is shaping up to be unseasonably warm.
A strong ridge of high-pressure building over the Western U.S. is the culprit for the warmth expected later this week. Temperatures on Tuesday were just about perfect with a high of 75 in the town of Jackson. However, we are going to rise well into the 80s later this week.
Highs will reach the low 80s in Jackson on Wednesday, then highs are currently projected to reach as high as 88 in Jackson on Thursday and Friday. It’s quite unusual for temperatures to soar this high during the first week of June. Typically, this type of warmth doesn’t arrive until July.
The temperatures later this week will at least challenge record highs. The daily records for both Thursday (June 4) and Friday (June 5) are 89 degrees, both of which were set in 1988.
Looking farther out, temperatures will start to cool down over the weekend and into early next week but still will remain above average for this time of year. Thunderstorm potential will start to increase next week, but significant moisture is not expected through at least mid-June.
The snowpack across the higher elevations in the Tetons is below average and the rate of snowmelt will only accelerate relative to average during this heat wave. Currently, the snow depth at the Rendezvous Bowl Plot at Jackson Hole Mountain Resort is 50 inches, which is the lowest value for June 1 in at least 14 years (records this late in the season only date back to 2008).
Despite the heavy rainfall we received in late May, it was not enough to put a dent in the drought conditions we’re currently experiencing. This is due to the fact that we need consistent wet weather over a more prolonged period, and also because evaporation rates are nearing their peak at this time of year given the long daylight and warm temperatures.
Unfortunately, early-season heat waves combined with pre-existing drought and low snowpack conditions are often precursors to bad fire seasons. For example, you may have noticed that the record highs we’ll be challenging later this week occurred in 1988 – the year of the devastating Yellowstone fires.
Another notable early-season heatwave that coincided with a low snowpack year was in 2003, when Jackson experienced its earliest 90-degree temperature on record on May 29 of that year. This was also a bad summer for wildfires in the Greater Teton-Yellowstone Region.
It remains to be seen what will happen this summer, and perhaps we’ll get lucky, but now would be a good time to start preparing for what could be an active fire season. At least in the present moment, we can enjoy the warm, sunny weather and smoke-free skies.
Alan Smith, Meteorologist
