textproduct: Western and Central Wyoming

KEY MESSAGES

- Scattered showers and a few embedded thunderstorms continue through Monday evening, with a few light showers lingering into the early morning hours Tuesday.

- Monsoon moisture continues to stream across the region leading to another round of widely scattered showers and thunderstorms Tuesday afternoon. The best chances will be in Sweetwater County and the northwest mountains.

- This pattern remains in place through the week, with above normal temperatures and scattered showers and thunderstorms developing each afternoon. Wednesday represents the best chance for more widespread showers and storms.

UPDATE

Issued at 1007 AM MDT Mon Jul 27 2026

More clouds today as monsoonal moisture lingers over the area with a weak weather system moving through. Showers, and the occasional storm, has persisted through the morning. Thunderstorms should become more common by early afternoon as the shortwave moves through in conjunction with peak daytime heating. Gusts to 50 mph are possible with these storms. Interestingly, the HRRR model has a long line of gusty winds 50 to 55 mph accosted with the main push of showers and storms from western WY starting about 2pm, moving east through the area through about 9pm. Will see if this trend holds for each hour's update. Otherwise, have kept temperatures today less than yesterday given the expected cloud cover. Increasing smoke will also occur over the area, mainly northern WY tonight into tomorrow with the fires in the western US, as well as a plume of smoke coming from the southwest associated with the Nevada fires.

DISCUSSION

Issued at 231 AM MDT Mon Jul 27 2026

The dominant western ridging pattern holds firm again today, the H5 ridge still anchored on the Four Corners region. The southwest tap of monsoon moisture continues today, and most models are bringing an increase in moisture during the next 6 to 12 hours. With warm temperatures still in place, daytime showers and thunderstorms will again develop late this morning and continue into the afternoon, moving to the northeast. The increased moisture and shortwave energy passing through today will bring a better chance for measurable rainfall from any thunderstorm, but the good forward motion of any storms will keep the chance for flooding low. Current cloud cover and any cover from thunderstorms today will keep temperatures lower than Sunday. Highs will still be above normal, but will hold in the low to mid 90s through the afternoon.

Tuesday will be similar to today, with very warm temperatures during the day. Ample moisture will tap this heat for scattered showers and thunderstorms during the afternoon. Midlevel support may be more limited, so showers might end up more isolated.

Wednesday another more vigorous shortwave comes around the ridge through Wyoming, which is expected to bring a much better chance for showers and thunderstorms. After this feature passes through, models are shifting the ridge slightly to the west through the rest of the week into the upcoming weekend. Models are noting a significant drop in moisture, as the monsoon moisture gets cut off. This would lead to much drier and warmer period heading into the weekend.

AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/

Issued at 1000 PM MDT Mon Jul 27 2026

VFR conditions are expected over the next 24 hours. Residual showers will continue over the northern half of the forecast area as they move toward the northeast through 12Z. Skies will become partly cloudy to mostly clear across the area through 18Z. Showers and thunderstorms will develop over the western mountains between 19Z and 21Z. An additional wave of showers and thunderstorms will develop off the Uinta Mountains and move into Sweetwater County by 21Z. The convective activity from both of these areas will move to the east-northeast into the central basins. PROB30 groups are included for terminals most likely to be impacted, namely, KJAC, KBPI/KPNA, KCOD and KRKS. Brief heavy rain and erratic outflow winds gusting 30 to 40 kt will be the primary threats once again with any storm that does pass near TAF sites. Confidence is too low to include a PROB30 group for KCPR between 02Z and 05Z Wednesday, as the remaining showers over Johnson/Natrona counties exit to the east. Winds will be light (11kt or less) through the TAF period, outside of any aforementioned outflow boundary.

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

Air Quality Alert until 1 PM MDT Tuesday for WYZ010.