textproduct: Western and Central Wyoming

KEY MESSAGES

- Temperatures will warm into 70s and 80s under mostly sunny skies this afternoon. There is a 15% to 30% chance of virga, light rain, and a few rumbles of thunder from the Uinta Mountains to Midwest from 1PM to 8PM. Gusty 40 to 50 mph winds could occur around any virga or light rain.

- Low light rain and thunderstorm chances (15%) exist Wednesday evening and overnight, mainly across western Wyoming. Shower and thunderstorm chances (20% to 40%) become confined to far northern Wyoming on Thursday.

- High temperatures through the week and into the upcoming weekend are forecast to be in the 70s and 80s, with highs reaching the low 90s on Saturday east of the Divide.

- Warm, dry, and breezy winds will bring elevated to near critical fire weather conditions through at least Saturday. Forecasted minimum relative humidity values are in the 8% to 15% range with afternoon wind gusts in of 20 to 35 mph.

UPDATE

Issued at 1227 PM MDT Tue Jun 2 2026

The forecast remains on track for this afternoon with southwest flow aloft and the passage of an embedded shortwave. A area of vorticity associated with the shortwave is forecast to be located from the Uinta Mountains to Midwest this afternoon. As the energy treks northeastwards, there will be just enough mid-level moisture and boundary layer instability (200 to 600 J/kg) to focus isolated shower activity across the Wind Corridor (up to 30% chance). However, virga or only light rain showers are expected with minimal accumulations due to the dry low levels. Dewpoint depressions this afternoon will be in the 35 to 45 degree Fahrenheit range, so any virga or light shower could produce gusty 40 to 50 mph outflows. A few thunderstorms cannot be ruled out across the aforementioned area, however, the chances of a thunderstorm are less than 20% given overall weak updrafts. This virga, light shower, and thunderstorm potential exists from 1PM to 8PM. Otherwise, widespread breezy winds are expected with high temperatures in the 70s and 80s under mostly sunny skies.

As mentioned in the morning discussion, a weak ridge will build across the Intermountain West on Wednesday. Given this ridge will be relatively weak, it will begin to break down late Wednesday afternoon and early evening ahead of Thursday's shortwave. As it breaks down, recent model guidance has begun to hint on increased vorticity aloft and some available mid level moisture across western Wyoming after 00Z Thursday. There is a 15% chance of light rain and even a thunderstorm Wednesday evening and overnight in the aforementioned area. Because the low levels will still be relatively dry, there is low confidence in how much liquid will make it to the surface. Thus, there is generally a 15% to 30% chance of a 0.01" of rain by Thursday morning. The forecast for Thursday remains on track with shower and thunderstorm chances (20% to 40%) for northern Wyoming as the shortwave trough and weak front trek across the state.

DISCUSSION

Issued at 209 AM MDT Tue Jun 2 2026

The meandering trough continues to spin along the MT/Canada border this morning, and will bring another weak shortwave around the south side during the day today. Light showers are already moving across greater Sweetwater County, sweeping to the northeast. Current timing for this trough is late morning into early afternoon, which will put most of the energy with the wave into NE WY during peak heating this afternoon. So the current band of showers will remain fairly weak with minimal accumulations into the early afternoon, and likely won't strengthen until after they reach NE WY. The remainder of western and central Wyoming will continue with mostly sunny skies and temperatures again reaching the 70s and 80s. With some wind gusts reaching 15 to 25 mph today, there will be some elevated fire weather concerns for lower elevations.

As this wave moves northeast tonight, weak ridging will build into western WY overnight, keeping things more stable during the day Wednesday. Skies will be mostly sunny again, with most areas seeing highs in the 80s.

Another shortwave moves mainly across Montana during the day Thursday, which will be close enough to bring showers to far northern WY Thursday afternoon. Stronger ridging builds Friday into the weekend, with even warmer temperatures in the 80s, with some 90 degree readings east of the Divide on Saturday.

AVIATION /00Z TAFS THROUGH 00Z THURSDAY/

Issued at 349 PM MDT Tue Jun 2 2026

Lingering showers and thunderstorms diminish in the first few hours of the period around KCPR and KRKS. Gusty west winds for most sites also decrease in the first few hours, following diurnal trends. After light winds overnight, winds increase between 18z and 20z. No precipitation expected Wednesday.

Please see the Aviation Weather Center and/or CWSU ZDV and ZLC for the latest information on icing and turbulence forecasts.

RIW WATCHES/WARNINGS/ADVISORIES

None.