JACKSON, Wyo. — A cool pattern settled into place across Jackson Hole during the past week with temperatures running about 5.5 degrees below average. A low pressure system brought widespread rain showers during the middle part of last week, though the heaviest rain fell just south of the area across Star Valley.
The map below shows 7-day precipitation percent of average, with an obvious uptick over Star Valley, while Jackson Hole and Teton County was close to average.
Temperatures were cooler than average across most of Wyoming and throughout the Rockies.
Overall, precipitation has been below average since about mid-April, but the past week’s cooler and wetter weather helped. Cooler than average temperatures this month have also prevented the vegetation from drying out too quickly, and soil moisture is slightly above average across Northwest Wyoming — good news heading into the start of fire season.
Weekly Weather Outlook — June 22 – June 28
We’ll see a beautiful start to the week with mostly sunny skies, warm temperatures and dry conditions on Monday and Tuesday. A trough of low pressure will approach during the middle part of the week, leading to increasing thunderstorm chances starting late on Wednesday before a more noticeable uptick occurs on Thursday with showers/thunderstorms possible throughout the day.
Monday-Tuesday:
High pressure is strengthening over the Rockies, and this will result in warmer temperatures and generally dry conditions over the next two days with highs in the mid to upper 70s.
Monday is looking rain and storm free over Teton County with a very low threat of an afternoon storm south and east of the area (Star Valley, Dubois, etc.). On Tuesday, an afternoon storm can’t entirely be ruled out over the Tetons and Jackson Hole, but it’s unlikely.
Wednesday:
Warm and dry conditions should prevail for most of the day with highs getting into the 80s. Thunderstorm chances will then increase late in the day and into the evening as a trough of low pressure approaches. Shower and storm activity will possible during the overnight hours as well.
Thursday:
This will be the most active day this week with scattered showers and possibly a thunderstorm during the morning hours giving way to a better chance of thunderstorms during the afternoon. Temperatures will be a bit cooler due to the increased cloud cover.
Friday:
Warmer and drier conditions will return with mostly sunny to partly cloudy skies and only a low threat for an afternoon thunderstorm.
Saturday-Sunday:
The weekend will start out with beautiful conditions on Saturday and minimal if any rain chances. Sunday will be an in-between day as a trough of low pressure and a rather strong cold front approach from the northwest. Temperatures should remain seasonally warm on Sunday but the chance for thunderstorms will increase during the afternoon/evening ahead of this system.
Cooler temperatures and higher rain chances can then be expected next Monday, although this system is still a week away so there is plenty of uncertainty with regards to timing and impacts. We’ll get more dialed on the details moving forward.
Alan Smith, Meteorologist
