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 /00Z TAFS THROUGH 00Z THURSDAY/

Issued at 400 PM MDT Tue Jul 28 2026

VFR conditions are expected to prevail across all terminals through the TAF period. A few showers and thunderstorms will be ending in the first couple of hours of the TAF period. However, all terminals are expected to remain dry through the overnight. Any breezy winds will weaken shortly after sunset with light winds through the overnight across nearly all terminals. Clouds will increase from the south-southwest by the predawn hours, with chances for showers over southern/southwestern portions late in the morning. PROB30 groups have been added to nearly all terminals from 17Z Wednesday to the end of the TAF period. Western locations such as KJAC, KPNA, KBPI, and KRKS are expected to see convection first with chances spreading to the remaining terminals after 18Z Wednesday. Otherwise, the main concerns will be frequent lightning, gusty outflow winds of 35kt, and brief periods of moderate to heavy rainfall. Mountains may be obscured at times mainly during the afternoon/evening hours Wednesday in association with developing showers and thunderstorms.

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.