textproduct: Western and Central Wyoming

KEY MESSAGES

- The next weather system moves across Wyoming today, bringing slight chances for showers and thunderstorms (~20%) across far northern WY.

- This system will also bring gusty southwest winds, with wind gusts of 30 to 40 mph across southern WY. These winds along with very dry air will bring near-critical fire weather conditions this afternoon.

- Very warm and dry conditions continue Friday through the weekend. Gusty winds Saturday will bring another day of near- critical fire weather concerns.

DISCUSSION

Issued at 243 AM MDT Thu Jun 4 2026

KRIW radar noting very light echoes this morning moving across northern WY from the the Northwest Parks into the Bighorn Range. Most of these are very high based, and dry air near the sfc is keeping most precip from actually reaching the ground. These showers are due to a passing shortwave across western WY north into Montana. The shortwave will be mostly through the area by noon, but showers and thunderstorms may linger across the northern Bighorns and northern Johnson County into early afternoon. With daytime heating and instability, some development of strong thunderstorms could build quickly in these areas before sweeping quickly to the northeast by midafternoon. Main threat with these storms would be gusty downburst winds due to very dry sfc conditions.

Farther to the south away from the shower activity, the pressure gradient around this system is tighter, which will result in some gusty southwest winds this afternoon. Forecasts gusts range from 30 to 40 mph from KRKS across the Green Mountains into Natrona County. This along with dry air already in place across the state will lead to near-critical fire weather concerns this afternoon. With most areas still in spring greenup, fuels are less receptive, so Red Flag Warnings will not be posted, but any fires that do spark will still have erratic behavior. Any burning is not advised today.

Once this system moves off this evening, the pattern buckles across the northern Rockies as a large trough drops down the west coast. This puts most of Wyoming in favorable ridging, deflecting systems away and allowing temperatures to soar. With H7 temps still forecast to reach 16 to 18C, sfc temps will jump well into the 80s west of the divide and into the 90s east of the Divide. Models have been trending upwards the past few days, with the latest forecast getting closer to daily record highs, and a couple areas within striking distance of 100 degrees.

Longer term forecast notes the west coast trough shifting farther east, knocking temperatures back down closer to normal. This will also shift better moisture into western WY, bringing a better chance for daily thunderstorms along the higher elevations of NW WY.

AVIATION /12Z TAFS THROUGH 12Z FRIDAY/

Issued at 510 AM MDT Thu Jun 4 2026

VFR conditions continue through the next 24 hours, with midlevel cloud cover sweeping through the region this morning. A couple light showers are noted on radar across northern WY, but most of this is not reaching the ground and not impacting local airports, but may cause variably gust winds aloft. Some showers and a few thunderstorms are possible from KCOD to KBYG this morning and early afternoon.

Gusty winds will build today, with most sites gusting above 25kts during the afternoon. KRKS and KCPR may gust higher this afternoon, but the peak wind would be in between these sites.

RIW WATCHES/WARNINGS/ADVISORIES

None.