textproduct: Western and Central Wyoming

KEY MESSAGES

- Warm, dry, and windy conditions with mostly clear skies continue Thursday. Afternoon high temperatures will be 5 to 10 degrees above normal east of the divide, and 3 to 6 degrees above normal west of the divide.

- Elevated to critical fire weather conditions persist today due to gusty afternoon west to northwest wind 20 to 30 mph and minimum relative humidity in the single digits to middle teens.

- Clouds will increase from west to east this afternoon with a slight chance of virga showers Thursday evening through Friday morning.

- The timing for the weekend storm system has been pushed to Sunday, meaning that Saturday will now be partly cloudy with a minimal chance for precipitation, warmer temps in the low 80s (except across northern WY), and breezy WSW winds.

- Precipitation chances have also been pushed to northern portions of Wyoming, as the track of the storm stays to the north. The cold front looks to move through Sunday night, leading to freezing temperatures across western portions of the state again, with cooler days on Monday and Tuesday.

DISCUSSION

Issued at 200 AM MDT Thu Sep 10 2026

Another day of critical fire weather conditions returns across the CWA today. RH values ranging between 7 to 15 percent will occur for most lower elevation locations this afternoon. Model forecasts for wind gusts have trended slightly downward for this afternoon. Winds will steadily increase through the afternoon, with gusts of 25 to 30 mph occurring over western portions of the forecast area and from the southwestern corner of the state to Natrona County. The higher gusts of 35 mph will be more confined to the eastern slopes of the Absaroka and Wind River Mountains. Burning of any kind continues to be highly discouraged! Otherwise, today will also be the warmest day of the week, with highs in the middle to upper 80s east of the Divide. Readings in the middle to upper 70s will occur west of the Divide.

Clouds will begin to increase from west to east through the afternoon. This will gradually lead to a chance for virga showers this evening into Friday morning. The central basins look to have the best chances between 01Z and 06Z with the main impact being gusty outflow winds. Winds will stay elevated for most areas and begin to decrease after 03Z Friday (9pm Thursday), with gusts up to 35 mph continuing over the east slopes of the Absaroka and Wind River Mountains through the rest of the night. Isolated virga showers will become possible over western portions by 12Z Friday morning and end by 18Z. These showers will be part of a larger push of moisture from UT/ID moving over the Cowboy State. This influx of moisture will also be the cause why humidity values will not drop below the critical threshold Friday afternoon.

The timing for the cold front has been pushed toward late afternoon, moving through Jackson, Cody and Kaycee by 00Z Saturday (6pm Friday). Temperatures will be slightly cooler east of the Divide as a result, especially for northern portions of the CWA. Widespread wind gusts of 30 to 35 mph remain in the forecast for Friday, keeping fire weather conditions elevated. The front will make it to the Divide by 06Z Saturday, becoming stationary through the rest of the night into Saturday morning.

The forecast for the weekend storm system has shifted dramatically this run. The storm system will drop southward along the West Coast Friday night into Saturday, a track that is much further west than previous runs. This will cause the aforementioned cold front to retreat northward Saturday afternoon, due to an increase in southwesterly winds. Initial indications show the front getting pushed into the Bighorn Basin and Johnson County by Saturday evening. Conditions are expected to remain dry until Sunday morning, as the storm begins to track over the Northern Rockies. Precipitation looks to stay confined over northern portions through the day Sunday as the storm stays further north in MT. The associated cold front will push through the Cowboy state Sunday night, clearing the forecast area by 12Z Monday. Sub-freezing temperatures will return to western portions, with readings in the upper 30s to lower 40s elsewhere. Dry and cooler conditions will be in place Monday, with highs in the 60s to near 70 degrees across the area. Another cold front looks to clip northern portions on Wednesday.

AVIATION /18Z TAFS THROUGH 18Z FRIDAY/

Issued at 1122 AM MDT Thu Sep 10 2026

Westerly zonal flow prevails across the forecast area through midday Friday. A batch of cloudiness and embedded showers across the northern Great Basin will track to the western border by Thursday evening and traverse the region overnight. There is a slight chance of light showers at KJAC and perhaps KBPI and KPNA between about 09Z-13Z/Friday, but have not placed PROB30 in any forecast at this time. Much of the increased mid-level cloud deck will lead to virga showers overnight and Friday morning. Westerly surface wind continues to increase at most terminals by 20Z/Thursday. KRIW and KLND should again see a favorable west- northwest wind 10-20kts toward 00Z/Friday whichi lingers into the evening hours, while KWRL stays less than 10kts. Other terminals see winds decrease by 03Z/Friday. The gusty westerly wind increases at many terminals between 15Z-18Z/Friday ahead of an approaching afternoon cold front from the north. Occasional mountain top obscurations between 07Z-15Z/Friday.

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 200 AM MDT Thu Sep 10 2026

Winds have trended downward slightly for this afternoon and will gradually increase through the afternoon. Wind gusts of 25 to 30 mph are now expected, with higher gusts of 35 mph expected in zones 286 and 288. Critical RH values between 7 and 15 percent will occur in most lower elevation zones this afternoon.

Clouds will increase from west to east through the afternoon. Virga showers will be possible in the Wind River and Bighorn Basins between 1800 and 2300. Wind gusts around 25 mph will be possible from any outflow boundary. RH recovery will be fair to poor once again tonight for zones east of the Divide.

Virga showers will be possible over western portions Friday morning. This increase in moisture will keep RH values from dropping to critical thresholds, ranging between 17 and 25 percent. A cold front will drop southward late in the afternoon reaching the Divide Fright night.

RIW WATCHES/WARNINGS/ADVISORIES

Red Flag Warning until 9 PM MDT this evening for WYZ286>288.

Red Flag Warning until 9 PM MDT this evening for WYZ277>280- 289-300.