textproduct: Western and Central Wyoming

KEY MESSAGES

- Warm, dry, and breezy conditions may lead to elevated fire weather conditions across portions of the state again on Friday.

- An approaching disturbance looks to bring widespread chances for showers and thunderstorms over the upcoming weekend. The best chances remain along the Continental Divide and areas east, especially across the Bighorns and Absarokas.

- The first week of summer is looking quite warm with daily chances for showers and thunderstorms.

UPDATE

Issued at 1215 PM MDT Thu Jun 18 2026

Not much to update regarding the forecast as warm and dry conditions will persist today into Friday. This will keep elevated to near critical conditions possible during the afternoon and evening today and tomorrow. A stray shower or two cannot be ruled out Friday afternoon/evening mainly over portions of far southwestern WY. Otherwise, the focus turns to the weekend, which looks to bring the next chance for showers and thunderstorms. Models remain in good agreement with the best chances for precipitation being across central and northern WY. Locations such as the Absarokas and Bighorns currently look to have the best chances for wetting rains. The first week of summer looks to be on the warm side with chances for showers and thunderstorms possibly arriving by the middle of the week.

DISCUSSION

Issued at 214 AM MDT Thu Jun 18 2026

A pleasant day is on tap today, with seasonal temperatures and mostly sunny skies. The one negative aspect will be northwest winds gusting up to 30 mph over areas west of the Divide after 18Z. Fire weather conditions will continue to be elevated to critical this afternoon, with the highest concern being over southern portions where the aforementioned winds will combine with humidity values as low as 8%.

The rest of the forecast remains on track with little changes from previous packages. A ridge will build over the region from the west Friday, marking a return for temperatures in the upper 80s to near 90 degrees. Fire weather conditions will continue to be elevated to critical, with critical RH values (<15%) occurring across areas west of the Divide, including the western valleys, and central portions of the CWA. Mid to high clouds will begin to increase, in advance to the incoming remnant Pacific low. There is a 10% chance for a virga shower to occur under these clouds through the afternoon.

Chances for precipitation return for the weekend, as the Pacific low move over the region. Northern portions of the CWA look to have the best chances to receive any precipitation, with forecasted rainfall amounts trending downward slightly between 0.25" to 0.50" over Saturday, Sunday and Monday. Locally heavy rain remains possible from these storms, as precipitable water values of 0.60" to 1" are still forecasted. Precipitation chances could linger into Monday, as a Canadian cold front moves over the area. Dry conditions return to the region Tuesday, as a strong area of high pressure develops over the Desert Southwest. Initial indications suggest that shortwaves will move over the PACNW/Northern Rockies from Wednesday to Friday, keeping precipitation chances up and the ridge suppressed to the south.

AVIATION /00Z TAFS THROUGH 00Z SATURDAY/

Issued at 514 PM MDT Thu Jun 18 2026

VFR conditions prevail at all terminals through 00Z/Saturday. West- northwest flow aloft gradually begins to back toward the west and eventually southwest ahead of a Pacific weather system set to arrive for the weekend. Initially, high cloud cover spreads across the area tonight and Friday morning. There could be enough mid-level moisture to set off very isolated showers over southwest Wyoming late Friday afternoon. At this time, no impacts to west of the Continental Divide terminals. As for wind, ongoing west-northwest wind gusting 18-26kts decreases 01Z-02Z/Friday. Westerly surface wind 14-22kts returns to the western terminals between 18Z-20Z/Friday. Terminals east of the Divide see a northerly wind receive a secondary surge Thursday evening as winds gust 14-22kts. These speeds diminish between 07Z-10Z/Friday leaving northeasterly wind of 10kts or less by 12Z/Friday, which persist through Friday.

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 214 AM MDT Thu Jun 18 2026

Elevated to critical fire weather conditions continue today, with critical RH values across southern zones, as well as zones 280 and 283. West-northwest winds, with gusts up to 30 mph will be confined to areas west of the Divide in the afternoon. Northeasterly winds increase over zones 280/281 after 1900, with gusts up to 30 mph. These winds will slowly decrease overnight tonight, ending by sunrise Friday morning.

Similar conditions return Friday, with westerly winds gusting up to 25 mph being mainly confined over areas west of the Divide. There will be a 10% chance for a virga shower across the area through the afternoon.

RIW WATCHES/WARNINGS/ADVISORIES

None.