textproduct: Western and Central Wyoming

KEY MESSAGES

- Widely scattered showers and thunderstorms persist across far western and far southern Wyoming until shortly after sunset Tuesday. Brief heavy rain and gusty outflow wind are the primary hazards, with gust potential greatest in the south.

- Moisture increases from the southwest beginning early Wednesday morning and spreads north through the day. Showers and thunderstorms becoming widespread as the day progresses.

- The bulk of the monsoon moisture shifts east beginning Thursday, which decreases rain chances while allowing for warmer temperatures to return to the region. Readings will likely reach the 90s and lower 100s Saturday and Sunday.

UPDATE

Issued at 1232 PM MDT Tue Jul 28 2026

With less cloud cover today, warmer temperatures will be in place, with highs in the upper-80s to upper-90s across the area. The latest hi-res models have isolated showers and storms mainly across western and southwestern Wyoming this afternoon. Outflow gusts to around 40 mph would be the most likely outcome from any shower or storm. Smoke from the west is also around today, mainly across northern Wyoming, but some will be across the whole state. Conditions improve some for Wednesday, with smoke then increasing over northwestern Wyoming Wednesday night.

DISCUSSION

Issued at 241 AM MDT Tue Jul 28 2026

The active monsoon pattern of the past couple weeks that has brought beneficial rainfall looks to be finally shifting the rest of the week. The H5 ridge placement centered on the Four Corners has been efficient in drawing moisture northward, and will continue today to trigger some shower activity for WY. Today, the focus of moisture looks to be more across southern WY, where the best chances for precipitation are setting up this afternoon. Some brief drying is noted across northern WY today, so shower activity will be more limited, and focused on higher elevations. The lower moisture for most of the state will bring decreased cloud cover, allowing temperatures to jump back well above normal. Areas east of the Divide will jump into the mid to upper 90s, while southern WY, with the better shower chances and cloud cover in the afternoon, will still reach the mid to upper 80s.

A final push of deeper monsoon moisture surges northward tonight, along with another shortwave wrapping around the ridge. This will bring much better chances for numerous showers and thunderstorms for the day Wednesday. Rainfall amounts will be beneficial again, but storm motions will be high enough to preclude most flooding concerns during the afternoon.

Once this shortwave sweeps northeast Wednesday night, the H5 ridge bulges to the west, effectively shutting the door on the monsoon flow, and instead drawing much drier air from the Great Basin into the state. This will effectively shut down rain chances for the rest of the week into the upcoming weekend. The ridge also bulges back to the north, bringing increasing temperatures across the state. Probabilities for 100 degree temperatures this weekend currently sit at >60% east of the Divide, and around 30% west of the Divide, including the greater Jackson region.

AVIATION /06Z TAFS THROUGH 06Z THURSDAY/

Issued at 1005 PM MDT Tue Jul 28 2026

VFR conditions are expected to prevail across all terminals through the TAF period. Conditions will remain dry through the rest of the night, as clouds increase from the south-southwest with SCT-OVC FL100-150 skies over the southern half of the forecast area by sunrise Wednesday. Showers will become possible over southwestern portions of the forecast area after 15Z, but should not impact KBPI/KPNA and KRKS until after 18Z. PROB30 groups remain in the forecast for all terminals starting around 20Z for thunderstorms occurring across the area through the afternoon. The main concerns will be frequent lightning, gusty outflow winds of 35kt, and brief periods of moderate to heavy rainfall. Have added additional PROB30 groups for KCOD and KJAC for continuing showers through the evening until 06Z Thursday. Otherwise, mountain tops may be obscured at times in association with the showers and thunderstorms and the overall increased cloud cover.

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

RIW WATCHES/WARNINGS/ADVISORIES

None.