textproduct: Western and Central Wyoming

KEY MESSAGES

- Elevated to critical fire weather conditions persist for portions of mainly central and southwest Wyoming this week due to gusty afternoon west to northwest wind 25 to 40 mph and minimum relative humidity in the teens.

- Freezing temperatures occur across the western valleys and basins early Wednesday morning, with the coldest locations seeing lows between 24 and 28. Sensitive outdoor plants are likely to be impacted by temperatures below 28 degrees.

- Daytime high temperatures remain near seasonal normals through the week, with minimal chances for rain.

- Confidence continues to increase for a storm system to arrive this weekend. An initial cold front pushes across the region Friday afternoon and evening, setting the stage for cooler and wetter weather Saturday and Sunday.

DISCUSSION

Issued at 223 AM MDT Wed Sep 9 2026

A Freeze Warning remains in effect for the western valleys, the Upper Green River Basin and southern Lincoln County this morning. Temperatures of 26 to 32 degrees are expected again in these areas, with more cold prone locations possibly dropping as low as 22 degrees.

Otherwise, dry conditions, clear skies and seasonal temperatures will be in the forecast again today. The main hazard will once again be fire weather. The lightest winds of the week are expected today, however elevated to critical fire weather conditions will be in place due to critically low RH values and wind gusts up to 25 mph. These winds will be primarily located from southern Lincoln County to Natrona County through the afternoon. The Fire Weather Watch that was issued for these areas has been upgraded to Red Flag Warnings as a result. Have also extended these new warnings into Thursday. Burning of any kind is highly discouraged due to the very dry conditions, regardless of how light the winds might be.

Critical fire weather conditions will become more widespread across the CWA again Thursday, as winds increase. Wind gusts of 25 to 35 mph will return for most areas in the afternoon. Exceptions will be for locations like eastern portions of the Bighorn Basin and northern portions of Johnson County. These winds will return for Friday afternoon as well. The main difference will be another dry cold front will move across northern areas east of the Divide. Initial indications are this front will become stationary along southern portions of the Bighorn Basin and Johnson County by midday Friday. Models remain split whether the front will push further southward through the overnight hours Friday and allow for the associated cold pool to infiltrate into the Bighorn Basin and Johnson County.

Moisture will begin to increase Saturday ahead of the incoming storm system, with the western mountains and central portions of the CWA having the best chances for precipitation Saturday afternoon into Saturday night. Snow levels will stay around 10kft through the night, so hunters/backcountry enthusiasts should prepare for snow. The storm itself will move over the Cowboy State during the day Sunday, with the coldest air staying over northwestern portions. Snow levels will range between 7000 and 8500ft in this area and most of the precipitation will stay over northern portions of the state. Freezing temperatures will return to western portions Monday and Tuesday mornings in the wake of this system, with readings in the middle 30s to lower 40s elsewhere. Monday will be a crisp autumn day, with highs in the 60s to near 70s degrees under mostly clear skies.

AVIATION /12Z TAFS THROUGH 12Z THURSDAY/

Issued at 440 AM MDT Wed Sep 9 2026

All terminals to be VFR/SKC through the entire forecast period within dry west-northwest aloft. Little more than late day few mid- cloud over the far north. Wind speeds are less than 10kt before daytime mixing allows for westerly surface 11-22kt to increase between 19Z-21Z at KCPR and terminals west of the Continental Divide. KRKS will likely see afternoon gusts 25-30kt. Some late day 9-13kt west- northwest winds surface for a few hours at KRIW and KLND. All winds decrease between 01Z-03Z/Thursday as the atmosphere decouples.

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

FIRE WEATHER

Issued at 230 AM MDT Mon Sep 7 2026

Fire Weather Watches in zones 277/278/279 have been upgraded to Red Flag Warnings and have been extended into Thursday. Winds will be the lightest across the area today, with gusts of 25 mph occurring from zone 277 to 280/300 and the mountain zones 285, 286 and 288. RH recovery will be fair to poor for most zones tonight. The only areas will good recovery will be zones 140/278 and the Jackson/Star Valleys.

Winds will increase across the area Thursday, with gusts of 25 to 35 mph occurring across most zones. The exceptions will be zones 275, 282 and the northern half of 281. RH recovery will be fair to poor again for most areas again Thursday night. Another cold front will move over northern WY Friday morning and looks to become stationary along southern portions of the Bighorn Basin and zone 281 by midday. Wind gusts of 25 to 35 mph will once again be widespread, however RHs are forecasted to be just above the critical threshold.

RIW WATCHES/WARNINGS/ADVISORIES

Freeze Warning until 9 AM MDT this morning for WYZ013-023- 025>027.

Red Flag Warning from noon today to 9 PM MDT Thursday for WYZ277>279.

Red Flag Warning until 9 PM MDT Thursday for WYZ280-289-300.