textproduct: Western and Central Wyoming

KEY MESSAGES

- Breezy wind, low humidity, and hot temperatures persist today. Red Flag Warnings continue for much of central and southern Wyoming through this evening.

- Isolated showers continue through the afternoon, mostly across southern and southwestern Wyoming. Outflow wind gusts to 60 mph are possible with this activity.

- Wildfire smoke will persist across the area, especially across northern Wyoming.

- Rain chances increase tonight and Wednesday as a system approaches. This will bring cooler temperatures and widespread rain chances into the weekend, with the best chances on Thursday (50-90%).

UPDATE

Issued at 119 PM MDT Tue Aug 11 2026

One last day of hot and mostly dry conditions is ongoing before a cooldown starts tomorrow. Convection will be more limited to southern Wyoming where modest instability will develop this afternoon. Outflow wind gusts up to 60 mph remain the primary concern. Hi-res models are showing increasing coverage of showers starting this evening as the first disturbance arrives from the approaching trough. This activity will move from southwestern Wyoming northeastward overnight, increasing in coverage east of the Divide through Wednesday morning. Cooler temperatures and widespread rain chances remain on track Thursday into the weekend.

DISCUSSION

Issued at 219 AM MDT Tue Aug 11 2026

Another day of hot and mostly dry conditions and hazy/smoky skies return today with the Four Corners high still in place. The zonal flow pattern aloft will continue, keeping conditions dry for most of the CWA today. Virga showers and dry thunderstorms will be possible across southern portions, roughly along and south of a Cokeville-to- Farson-to-Muddy Gap line. Instability remains very weak, so these will likely stay on the virga side just like what occurred yesterday. Wind gusts of 50 to 55 mph will be the main threat from these "Green Blobs". The other concern today will be critical fire weather conditions. Red Flag Warnings are in effect today between 18Z and 03Z Wednesday (12PM to 9PM) for all the same areas from yesterday except southern Lincoln County/Uinta County. RH values of 8 to 12% will be widespread east of the Divide and include the Jackson Valley and portions of Yellowstone. Overall, winds will not be as strong across the CWA this afternoon but gusts of 25 to 30 mph will occur in many of these areas. Needless to say, burning of any kind is highly discouraged today. Today will be the last day of this latest heat wave with highs in the middle 90s for most areas east of the Divide and upper 80s/lower 90s west of the Divide.

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. Clouds will increase tonight into Wednesday morning leading to mostly cloudy skies across the forecast area. Temperatures will be cooler as a result from increased cloud cover, about 3 to 8 degrees cooler. Showers and thunderstorms will be widely scattered through the day, with western portions having the best chances through the afternoon. The HRRR brings an area of showers over the Wind Corridor (Sweetwater to Natrona County), starting around sunrise and exiting early in the afternoon. Instability remains rather weak, likely due to the clouds, so not expecting any major threats. Wind gusts of 40 to 50 mph and locally heavy rain will be the most likely.

The trend of cooling temperatures 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 and wetter conditions continue Friday, as the trough exits over the Northern Plains and the southwest flow pattern continues. This will be due to a strong high over the Deep South/Gulf Coast and a longwave trough over the West Coast. This will allow embedded shortwaves to move over the Cowboy State, generating chances for convection across the area each day from Friday into the middle of next week. The threat for locally heavy rain will also continue as the monsoonal moisture stays in place as a result of this pattern.

AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/

Issued at 1101 AM MDT Tue Aug 11 2026

VFR conditions prevail through the period. Lingering smoke is still present across the area. The thickest is across northern Wyoming, impacting KCOD and KWRL the most. THunderstorm chances are very limited today, mainly around KRKS this afternoon.

Tonight, some weather models bring in light rain chances from the southwest starting after 04Z. Models vary a lot in timing and location, so confidence is low. For now, have included PROB30 groups for KBPI and KPNA, with increasing clouds elsewhere.

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

FIRE WEATHER

Issued at 219 AM MDT Tue Aug 11 2026

Red Flag Warnings are in effect again for zones in central and southern portions of the state. Zone 277 is the notable exception from Monday. Hot temperatures, critical RH values and gusty winds will return to these areas. Virga showers/dry thunderstorms will be confined to zones 277, 278, 279 and 289 this afternoon. Outflow wind gusts of 50 to 55 mph will be possible from any shower or thunderstorm due to the dry conditions. Conditions improve Wednesday with temperatures 3 to 8 degrees cooler across the area with mostly cloudy skies and increased chances for precipitation. This trend of cooler and wetter conditions continues through the rest of the week into the weekend.

RIW WATCHES/WARNINGS/ADVISORIES

Air Quality Alert until noon MDT Wednesday for WYZ001>011-019.

Red Flag Warning until 9 PM MDT this evening for WYZ140- 278>281-283-285>287-289-300.