textproduct: Western and Central Wyoming

KEY MESSAGES

- Isolated light virga showers or a light rain is possible across southern and central Wyoming through midnight tonight.

- Low humidity, hot temperatures, and breezy winds are expected again on Tuesday afternoon. Red Flag Warnings are in effect for much of central and southern Wyoming from Noon to 9PM on Tuesday.

- Wildfire smoke persists across the area, especially across northern Wyoming.

- A pattern change will bring cooler temperatures and increased rain chances beginning Wednesday. Thursday brings the best chance for widespread rain (50-80%).

UPDATE

Issued at 316 PM MDT Mon Aug 10 2026

Scattered showers and thunderstorms will continue to move across the area this afternoon, focused most across central and southern Wyoming where mesoanalysis shows 250-750 J/kg of SB CAPE. With 1,500 J/kg of DCAPE observed on the 18Z RIW sounding, strong outflow wind gusts to 60 mph remains the primary concern. This activity will wane with sunset. Very similar conditions are expected on Tuesday, though convection chances will be mostly limited to areas along and west of the Divide. Elevated to critical fire weather conditions continue for much of the area, with most of the Red Flag Warnings now reissued for Tuesday.

DISCUSSION

Issued at 224 AM MDT Mon Aug 10 2026

The Four Corners high will remain in place, along with a zonal flow pattern over the Cowboy State today. Similar conditions from Sunday will return across the area with temperatures remaining above normal and critical fire weather conditions in place. Westerly winds, with gusts of 25 to 35 mph, will increase after 18Z across much of the CWA. The notable exception will be most areas of the Bighorn Basin, where winds will struggle to gust up to 20 mph. Virga showers/dry thunderstorms will also develop over the southern half of the forecast area early in the afternoon, with the Wind River Mountains, the northern end of the Salt River/Wyoming Ranges and the western half of Sweetwater County having the best chances for a shower or storm. Wind gusts up to 55 mph will be possible due to large dewpoint depressions that will be in place once again this afternoon. Most of the convection will end across the area by sunset. Red Flag Warnings have been reissued for areas east of the Divide and southern portions of the CWA from 18Z to 03Z Tuesday (12PM to 9PM) due to aforementioned critical RH values, gusty winds and dry thunderstorms. Skies will remain hazy from smoke will continue today, especially over northern portions.

Another day of hot and dry conditions return Tuesday. Highs in the middle 90s will occur again for most areas east of the Divide and upper 80s/lower 90s west of the Divide. Wind gusts of 25 to 35 mph will occur again, but are not expected to be as widespread. Red Flag Warnings will likely only be needed for a few zones as a result. Needless to say, the hazy/smoky skies will continue across the area as well.

The pattern will begin to shift Wednesday, as the Four Corners high weakens and erodes and the flow aloft over the Cowboy State turns more southwesterly irt an approaching trough. Precipitable water values will increase through the day as a result, with values approaching 1". This won't be as strong as the surge of monsoonal moisture that occurred a few weeks ago in July, but the threat for locally heavy rain/localized flash flooding will certainly be in place. Convection looks to be rather isolated so far, but temperatures will be slightly cooler from increased cloud cover and a weak cold front. This trend continues into Thursday, with temperatures dropping into the 70s to near 80 degrees. Thursday also looks to be the best chance for widespread precipitation, especially across western portions of the state, as the trough moves over ID. The cooler conditions continue Friday, as the trough exits over the Northern Plains. Convection will be more widely scattered as weak shortwaves move over the area through the continued southwest flow aloft. The threat for locally heavy rain will also continue as the monsoonal moisture stays in place. This trend will continue through the weekend, as shortwaves continue to rotate over the region from the southwest.

AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/

Issued at 947 PM MDT Mon Aug 10 2026

VFR flight conditions are forecast to prevail through the TAF period. However, brief periods of MVFR visibilities and mountain obscurations are possible due to wildfire smoke over the area, especially at KJAC, KCOD, KRIW, KLND, and KWRL. Confidence remains rather low in the timing of the thicker smoke and lower visibility. Light winds are forecast overnight before increasing after 18Z at most terminals. Winds are forecast to increase as early as 16Z at KCPR. Winds gusts in the 18kt to 30kt range are expected Tuesday afternoon before decreasing by 01Z/02Z Wednesday. There is a 30 percent chance of virga or a thunderstorm, capable of 30kt to 40kt outflows, in the area of KRKS between 20Z and 24Z Tuesday. Additionally, there is up to a 15 percent chance of virga showers or a thunderstorm in the area of KJAC, KRIW, KCPR, KLND, KBPI, and KPNA after 00Z Wednesday.

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

FIRE WEATHER

Issued at 224 AM MDT Mon Aug 10 2026

Red Flag Warnings have been reissued for zones in central and southern portions of the state. Hot temperatures, critical RH values and gusty winds will return to these areas, along with chances for dry thunderstorms. Outflow wind gusts up to 55 mph will be possible from any shower or thunderstorm due to the dry conditions. Similar conditions return Tuesday and Warnings may be needed again, but not all zones will reach criteria. Winds do not look to be as widespread with no threat for dry thunderstorms.

RIW WATCHES/WARNINGS/ADVISORIES

Red Flag Warning from noon to 9 PM MDT Tuesday for WYZ278>281- 283-285>287-289-300.