textproduct: Western and Central Wyoming

KEY MESSAGES

- Air Quality alerts are in effect across the whole CWA through Thursday 11 AM.

- Elevated to critical fire weather conditions across portions of the state this afternoon/evening especially southwestern WY where Red Flag Warnings are in effect.

- Temperatures will begin to rise again today, with heat again peaking Friday and the weekend. Some locations may see 100 degree high temperatures once again.

- Chances of showers and thunderstorms remain rather low though the weekend, although chances may increase next week as monsoonal moisture may return to the area.

UPDATE

Issued at 1126 AM MDT Wed Aug 5 2026

Air Quality Alerts have been reissued and expanded to now include all of Wyoming. These are in effect from 11 AM Wednesday through Thursday 11 AM due to increasing smoke from wildfires across the PACNW. Otherwise not much else to update this morning regarding the forecast. Elevated to critical fire weather conditions will be likely across much of the area this afternoon and evening. Southwestern WY is currently in a Red Flag Warning due to having the best chances of seeing wind gusts of 25 mph or more at times this afternoon. Thursday may see another day of near critical fire weather conditions especially across southwestern WY where the strongest winds are forecast. As of this morning no additional fire related highlights will be issued due to the borderline wind speeds for much of the area. However, if forecast wind speeds do increase, then Red Flag Warnings may be needed but that is likely a decision for the overnight shift to make. Temperatures continue to be forecast to warm back up into the mid to upper 90s by Friday. These warm above normal temperatures look to persist into the weekend with highs possibly flirting with the century mark for some locations east of the Divide. Precipitation chances continue to look abysmal with nonzero chances through the weekend.

DISCUSSION

Issued at 158 AM MDT Wed Aug 5 2026

There are weird things that hit you when working at night, especially on a lack of sleep (that is me tonight). I just had a memory from when I was 12 years old back in 1983. The memory is the first "R" rated movie I was able to see. And that movie was the classic comedy "48 Hours" starring Nick Nolte and Eddie Murphy. And you may be asking, how does this relate to the weather? Well, the premise of the movie was the Eddie Murphy's character was on a 48 hour pass from prison to help Nick Nolte catch a criminal. And 48 hours is about the time a relief we will have from the relentless heat over much of the past month. The past couple of days have been rather nice, despite the smoke. However, like Murphy's pass came to an end, our relief from the heat will come to an end starting today but especially later in the week.

The reason is the ridge that had retreated southward somewhat after the passage of the cold front Sunday night and Monday will begin build back northward today and bring another period of above normal temperatures starting today in southern Wyoming and building across much of the area into the weekend. It seems to be following a pattern, much like the past several weeks, with the warmest high from Friday into the weekend. The 700 millibar temperatures rise to plus 17 today across the south, rising as high as plus 21 by the weekend. Most guidance is consistent in keeping the warmest temperatures across central and southern Wyoming, with somewhat cooler temperatures aloft over northern Wyoming. It will still be above normal even there though. At this point, it does not look quite as hot as the past few weekends though. We will be entering solar autumn tomorrow, so the sun won't be quite as strong. Nights are also getting noticeably longer, allowing more time to cool off and less time to warm up during the day. And, smoke from the wildfires over the Pacific northwest and now in western Wyoming may keep temperatures a few degrees cooler. Nevertheless, from Friday through Sunday, locations in the Wind River and the southern Big Horn Basin still have around a 1 in 2 chance of high temperatures over 100 in locations under 5000 feet in elevation.

The other concern will be potential critical fire weather. Humidity will remain low thorough the period. The main variable will be wind. The wind will remain rather gusty across southern Wyoming today. So, we will hoist a Red Flag Warning for Sublette, Sweetwater and southern Lincoln Counties starting at noon today. We do have a bit of a conundrum for much of the rest of the workweek. The threat of critical fire weather may spread further to the north into central Wyoming. Humidity will remain below critical levels through the weekend. However, wind will be borderline for much of the week. With the uncertainty, we will take things one day at time. We will let the day crew reevaluate and see if warnings need to be moved northward or extended. Right now, the chance is around 50 - 50.

As for precipitation, the chance is basically zero through Friday. A bit of moisture may try to move into western Wyoming on Saturday but it is of the mid level variety and may produce little or no rain and possibly dry lightning. Somewhat deeper moisture may return for Sunday and into next week as the ridge again retreats to the south and some deeper monsoonal moisture may try to return to the area, but trying to pick out a more active day is nearly impossible this far out. With the ridge retreating to south, temperatures should also cool off again, returning to more typical levels for early and mid August. However, the main story for the next several days will be another return of the heat we have seen so frequently since the around the Fourth of July.

AVIATION /18Z TAFS THROUGH 18Z THURSDAY/

Issued at 1108 AM MDT Wed Aug 5 2026

Conditions are expected to be dry through 18Z Thursday. The main flight concern is the potential for visibility restrictions due to haze and smoke across the state due to wildfires in the western United States. Most locations could see periods of MVFR visibilities, especially after sunset today/Wednesday. Confidence in the exact timing and duration of MVFR visibilities remains low, thus the timing represents the best timing estimate. Otherwise, breezy afternoon winds are expected at KJAC, KRKS, KCPR, KPNA, and KBPI with gusts around 25kts possible. Winds diminish shortly after sunset and remain relatively light overnight.

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 158 AM MDT Wed Aug 5 2026

A combination of humidity falling into the single digits and a gusty west to southwest wind will bring critical fire weather to southern Wyoming today, with Red Flag Warning in effect from noon until 9 pm today. Elsewhere today, relative humidity will fall below 15 percent and in many locations under 10 percent. However, wind should remain below critical levels. Elevated fire weather is likely for almost all the area though. Elevated to critical fire weather is possible again on Thursday but wind is too borderline right now to issue or extend Red Flag Warnings at this time.

RIW WATCHES/WARNINGS/ADVISORIES

Air Quality Alert until 11 AM MDT Thursday for WYZ001>020- 022>030.

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