textproduct: Western and Central Wyoming

KEY MESSAGES

- Warm, dry, and breezy conditions will continue through the week. Chances for rain will be low (5 to 10 percent), mainly limited to the mountains.

- Wind gusts of 30 to 40 mph and humidity of 10 to 20 percent will lead to widespread elevated to critical fire weather conditions on Tuesday and Wednesday.

- A dry cold front quickly moves through areas east of the Divide early Wednesday morning, reaching the Divide shortly after sunrise. Highs will be 5 to 15 degrees cooler as a result.

- Chances for precipitation return for the weekend, with the northern half of the forecast area having the best chances.

DISCUSSION

Issued at 253 AM MDT Tue Jun 16 2026

A subtle ridge is building in from the west currently, ahead of an approaching trough and cold front. This will lead to high temperatures in the upper 80s to lower 90s in the Wind River and Bighorn Basins and portions of Natrona County. Northwest winds will increase through the morning, with gusts of 25 to 30 mph expected for most areas between 16Z and 18Z (10AM and 12PM). These winds will continue to increase with gusts 30 to 40 mph expected after 20Z across much of the CWA. These winds, combined with RH values below 15% and above normal temperatures, will lead to widespread critical fire weather conditions. A Red Flag Warning is now in effect for portions of Natrona County, due to the critical fuels in this zone. Conditions will remain dry, with a 10% chance for virga showers/dry thunderstorms over eastern portions of the Bighorn Basin up against the west slopes of the Bighorns and crossing over Johnson County between 00Z and 06Z Wednesday.

The aforementioned cold front will quickly move through areas east of the Divide late tonight/early Wednesday morning, reaching the Divide a few hours after sunrise. This will keep winds north- northeasterly in this area through the day, as well as dropping high temperatures 5 to 15 degrees cooler from Tuesday. Wind gusts of 35 to 45 mph will be in place over northern portions in the wake of the front, and southern portions as the front looks to remain stationary along the Divide through the rest of the day. Elevated to critical fire weather conditions will remain widespread, especially central and southern portions of the CWA, as well as the western valleys.

More seasonal conditions return for Thursday, with winds not being so strong. Gusts up to 25 mph look to be confined over areas west of the Divide in the afternoon. A ridge looks to build over the region from the west Friday, marking a return for temperatures in the upper 80s and lower 90s. Fire weather conditions will be elevated to critical on these days as well, with RH values dropping into the single digits across the south and possibly into central portions. Chances for precipitation return for the weekend, as the remnants of a Pacific low move over the region. For now, the northern half of the CWA looks to have the best chances to receive any precipitation. Locally heavy rain could occur from these storms, as precipitable water values of 0.75" to 1" are forecasted.

AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/

Issued at 435 AM MDT Tue Jun 16 2026

VFR conditions prevail at all terminals through the forecast period. The pressure gradient within northwest flow aloft tightens as a system moves into the Northern Rockies late Tuesday. This results in gusty west to northwest surface wind at all terminals, which develops between 16Z and 21Z. Wind gusts 25-35kt will be common after 20Z and these speeds continue through around 03Z before diminishing by 10-15kt. Shortwave energy moving across Montana this evening nudges a cold front into northern Wyoming around 06Z and continues southward toward KRIW, KLND and KCPR toward the end of the period. This leads to a northerly wind 10-14kt at KCOD and KWRL just prior to 06Z and at KRIW around 09Z. Current indications have the front reaching KCPR and KLND after 12Z Wednesday.

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 253 AM MDT Tue Jun 16 2026

Elevated to critical fire weather conditions expected through the week this week. Conditions will be the most critical today, with wind gusts of 30 to 40 mph expected across much of the forecast area. Above normal temperatures and widespread critical RH values will coincide with the winds. Thus, a Red Flag Warning is in effect for zone 280 where fuels are critical at this time.

A dry cold front will quickly move over areas east of the Divide late tonight/early Wednesday morning, turning winds more northerly in this area. Gusts of 30 to 40 mph will return for northern portions of the forecast area in the wake of the front, while southern portions (zones 277/278/279) also have northwest winds gusting 30 to 40 mph. RH values will be critical across the south, and portions of the Wind River Basin, as the front is expected to be stationary along the Divide through the day Wednesday.

RIW WATCHES/WARNINGS/ADVISORIES

Red Flag Warning from noon today to 9 PM MDT this evening for WYZ280.