textproduct: Western and Central Wyoming

KEY MESSAGES

- Temperatures east of the Divide will be 12-18F below normal today, in the wake of a cold front Friday night. Extensive cloud cover through Saturday evening will aid in the cooler temperatures.

- Lower elevation rain and mountain snow showers occur between mainly sunrise and noon across northern portions of the forecast area. The best chances (50 to 80 percent) occur over the Bighorn Mountains and Johnson County during this time.

- Conditions improve Sunday and lead into a warming trend starting Monday, with limited to no rain chances.

- Elevated to critical fire weather conditions will be in place starting Monday as well, with Tuesday looking to be the most critical.

DISCUSSION

Issued at 147 AM MDT Sat Jun 13 2026

The cold front reached the Divide early this morning and will cross the Divide after sunrise as it slowly continues southward today. An area of showers continues just north of the state line over southern MT. These showers will reach the Bighorn Basin and northern portions of Johnson County by the predawn hours. Most of the precipitation will occur in Johnson County and the Bighorns, where model trends have increased amounts close 0.50" near Buffalo and Powder River Pass between 12Z and 18Z (6AM and 12PM). This would result in snowfall amounts of 5-6" above 9000ft. There is currently no lightning occurring in these showers and none are expected through the rest of the morning, as conditions are relatively stable with temperatures in the 40s and lower 50s. These showers will dwindle by 18Z, with a 30 to 60% chance continuing over the Absarokas and Bighorns through the rest of the day. An isolated lightning strike could occur over these areas in the afternoon, but confidence is low. The rest of the forecast area will be dry and cool, with temperatures in the 50s to lower 60s east of the Divide and in the 60s and 70s west of the Divide. The progression of the cold front over southern portions will be slowed by northwest winds over southwestern portions of the state. The front will finally reach the Green River Basin after sunset, as the northwest winds weaken. Easterly wind gusts of 25 to 45 mph will occur across southern portions of the CWA behind the front through the night and into Sunday morning.

Seasonal temperatures will be in place across the CWA Sunday with highs in the upper 60s into the 70s. Conditions will be dry, except for very isolated showers possible over central portions throughout the day. Winds will be light as well, with gusts of 20 t0 25 mph occurring over the southern half of Sweetwater County.

A warming trend will begin Monday, with a northwest flow pattern aloft in place. Heights will rise Tuesday within this pattern, leading to high temperatures in the upper 80s to lower 90s in the Wind River and Bighorn Basins and portions of Natrona County. Temperatures will be slightly cooler Wednesday, as a cold front clips northern portions of the state. This looks to be the best chances for any precipitation next week as well, as much of the week looks to stay dry. Fire weather conditions will be elevated to critical through the week as well, with Tuesday looking to be the most critical.

AVIATION /12Z TAFS THROUGH 12Z SUNDAY/

Issued at 428 AM MDT Sat Jun 13 2026

West of the Divide...KBPI/KJAC/KPNA/KRKS Terminals.

SKC across the area through much of the TAF period, apart from periods of CU over the higher elevations in the afternoon. Wind gusts up to 20kt will develop by 17Z, becoming light (11kt or less) again by 01Z. The exception will be KRKS, which will turn northeasterly and increase to 35kt in the wake of a cold front. These winds will continue until 09Z, with a sustained wind around 13kt through the rest of the period.

East of the Divide...KCOD/KCPR/KLND/KRIW/KWRL Terminals.

MVFR to VFR ceilings have increased over the area from KCOD to KCPR in the last hour or so. These conditions will spread to KRIW/KLND by 15Z. VLIFR/LIFR ceilings will be possible at KCOD through 18Z, with rain expected through 15Z. Skies will become SCT-BKN and VFR across the area by 21Z, becoming BKN-OVC again by 01Z for KCOD, KRIW and KLND.

Mountain obscurations will be prevalent through 21Z, with mountain tops being obscured after 01Z.

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

RIW WATCHES/WARNINGS/ADVISORIES

None.