textproduct: Western and Central Wyoming

KEY MESSAGES

- Dense smoke continues tonight across most of northern and western Wyoming. Air quality remains unhealthy for sensitive groups.

- Gusty north to northwest winds through sunset today. A Red Flag Warning remains in effect until 9PM tonight across south and southwest Wyoming due to gusty winds and relative humidity values around 10 percent.

- Mostly dry weather is forecast over the next 7 days, with a warming trend beginning Wednesday. Temperatures return to the mid to upper 90s by Friday.

UPDATE

Issued at 1138 AM MDT Mon Aug 3 2026

A cold front trekked across the state this morning and brought cooler air to the entire area. 11 AM observations are indicating that temperatures east of the Continental Divide are running 10 to 20 degrees cooler and west of the Continental Divide are 5 to 10 cooler than 11 AM yesterday/Sunday. Gusty winds are also present today thanks to a tight surface pressure gradient behind the front and a 60kt to 80kt upper level jet overhead. These gusty 25 to 35 mph winds are contributing to two things on each side of the Continental Divide. Along and east of the Continental Divide a north wind is bringing smoke from the western United States wildfires into the area and causing reduced air quality. The strong west to northwest winds and low relative humidity across south and southwest Wyoming continues to result in critical fire weather conditions this afternoon. Fire weather conditions begin to improve around 9PM this evening as both wind diminishes and relative humidity increases. The smoke looks to hang around through at least Tuesday morning due to light east winds overnight keeping the smoke socked in.

The only change made to the forecast was the addition of light rain across northern Wyoming on Tuesday afternoon and evening as a shortwave trough treks across the area. There looks to be just enough mid and low level moisture and lift with the shortwave to support light rain. The northern Bighorn Mountains are expected to have the "greatest" chances of seeing rain due to favorable orographics. However, this will not be a meaningful rain by any means with less than a 15% chance of 0.1" of rain by early Wednesday.

DISCUSSION

Issued at 200 AM MDT Mon Aug 3 2026

WV imagery shows dry slotting conditions for much of the northern Rockies with the main finger of the PFJ well north into Canada. IR shows mainly clear skies for the state with high pressure building in from the south behind a weak shortwave that has pushed through much of the CWA east of the Divide. As such, a weak cold front has pushed through the state affecting mainly portions east of the Divide through early Monday morning. This will result in more of northerly direction for winds and temperatures up to 15 to 20 degrees cooler in the afternoon than that of Sunday. Areas west of the Divide, especially south and southwestern portions of the CWA will not see much of the affects. Westerly winds persist in these areas where gusts up to 30 to 35 mph are likely through sunset before easing into the overnight hours Monday into Tuesday morning. This will continue to the red flag conditions before weaker winds expected Tuesday onward through the work week.

Going forward, expect mainly dry conditions and a slight warming trend through the rest of the week and into the weekend. The only exception will be a shortwave that will skirt by to the northeast, that will have weak PoPs around 15 to 20 percent for the northern Bighorns and into Johnson County Tuesday evening through about midnight. Quick moving and progressive, this will have limited impacts and QPF of note. Temperatures will push back to well above average once again for Thursday and Friday with areas east of the Divide pushing triple digits once again east of the Divide possibly pushing some records as well. Nothing of note on the horizon outside of the increasing temperatures and elevated to near critical fire weather conditions, but no strong wind events look to occur as well. Longer term model solutions show a possible pattern change by early to mid next week as the upper level flow and upper high to the south weaken as trough digs down across the Pacific northwest. Time will tell, but in the meantime, enjoy the "cooler" Monday before temperatures push right back up throughout the week with no precipitation of note on the horizon.

AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/

Issued at 446 PM MDT Mon Aug 3 2026

Wildfire smoke will continue to be the main hazard over the next 24 hours as it continues to reduce VIS for terminals east of the Continental Divide. This smoke will spread west of the Continental Divide tonight into Tuesday. This smoke near the surface is thanks to the strong cold front trapping the smoke. This cold front is along the Divide today and will push west of the Divide tonight. VIS will most likely improve overnight to VFR, but this does not mean the smoke will exit the area. It will linger across the area over the next 24 hours and beyond, but some improvement is possible for northern terminals Tuesday. For now included prevailing HZ and 6SM at all terminals for Tuesday morning through Tuesday afternoon, but reductions to MVFR remain likely (60%) at times.

Wind remain quite breezy behind the cold front east of the Divide this evening. Wind will be breezy west of the Divide Tuesday afternoon. Overall wind will be below 10 knots tonight and 10-15 knots at the breezier terminals Tuesday afternoon. Isolated showers, mainly virga showers, are possible (10-20%) around the Absaroka and Bighorn Mountains Tuesday afternoon. Frequent partial mountain obscuration due to smoke and haze will continue through the TAF period.

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 200 AM MDT Mon Aug 3 2026

Behind a cold front, fire concerns should lessen across northern and central Wyoming with cooler temperatures and higher humidity. Critical fire weather conditions continue for southern and southwestern portions of the state due to warmer temperatures and lower humidity values below 10 percent Monday afternoon and early evening. Breezy westerly winds up to 30 to 35 mph persist leading to red flag conditions for these areas of the wind corridor.

RIW WATCHES/WARNINGS/ADVISORIES

Air Quality Alert until 11 AM MDT Tuesday for WYZ001>011- 016>020-022.

Red Flag Warning until 9 PM MDT this evening for WYZ277>279- 289.