textproduct: Western and Central Wyoming

KEY MESSAGES

- An isolated storm remains possible (10% or less) over the Bighorn, Absaroka and Wind River Mountains this afternoon.

- Smoke/haze will increase over western and central portions of the forecast area through the day.

- It will be dry Sunday through Tuesday of this coming week. Temperatures will be cool to seasonal with highs in the upper 70s to upper 80s. - A cold front will drop highs by up to 5 degrees on Wednesday and Thursday. This will bring low chances (20-30%) for showers and storms Wednesday afternoon.

DISCUSSION

Issued at 130 AM MDT Sun Aug 31 2025

Conditions are expected to be mostly dry for the rest of the Labor Day weekend and Tuesday, with temperatures ranging from the upper 70s to upper 80s. There is less than a 10% chance for showers to develop over the Bighorn, Absaroka and Wind River Mountains this afternoon. Winds will stay light, with periods of high clouds from time to time. The synoptic pattern this week remains largely unchanged: the Cowboy State will be sandwiched between an upper level ridge to the west and a strong developing longwave trough to the east. The influence of these two features could cause some variability for each side of the Divide. The main wrinkle today will be increasing smoke/haze across western and central portions of the CWA through the day. Most of the smoke will be from the numerous wildfires in central ID.

A cold front looks to move across areas east of the Divide by Wednesday. Models are now in better agreement with the timing and keep the colder air well to the east. The possibility for the first shot of fall weather has gone down and does not look like it will happen this week. Overall, the forecast looks to stay somewhat stable this week with mostly dry conditions and light winds. Additionally, these conditions will keep fire weather conditions from going critical.

AVIATION /12Z TAFS THROUGH 12Z MONDAY/

Issued at 400 AM MDT Sun Aug 31 2025

Weather conditions will be very uneventful over the next 24 hours with mostly clear skies and light wind. There will be a northwest breeze around 10 knots at KCPR Sunday afternoon, but elsewhere wind will remain below 8 knots through the TAF period. Areas of smoke may move toward the western TAF sites this afternoon, but conditions are expected to remain VFR at this time.

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

RIW WATCHES/WARNINGS/ADVISORIES

None.