textproduct: Western and Central Wyoming

KEY MESSAGES

- A few scattered rain showers linger across Fremont to Natrona Counties through early Friday morning before sunrise.

- Warmer and a dry rest of Friday in store ahead of the next weak system that will bring scattered showers and isolated thunderstorms for many locations east of the Divide Saturday. Strongest storms possible east of the Bighorns (20-30%) with gusty outflows the main hazard.

- Warming and dry trend for Sunday and for much of next week.

DISCUSSION

Issued at 100 AM MDT Fri May 8 2026

Northwest flow aloft continues across the CWA as depicted on WV imagery with the PFJ now retreated to the northeast coming out of Canada through eastern Montana to northeastern WY to the Great Plains. IR shows subsidence pushing in from the west as the ample cloud cover is pushing east out of the area by sunrise Friday morning. A few scattered showers linger across eastern Fremont and into Natrona County that will diminish and exit the CWA before sunrise as well.

Convergence and dry slotting expected for Friday with warmer temperatures (~5 degrees warmer than Thursday) with dry conditions expected. Some breezy winds west of the Divide and across the wind corridor, but nothing exceptional with an overall weak to moderate pressure gradient across the CWA. The next subtle shortwave will propagate down the northwest flow dropping a weak frontal boundary in from the north come Saturday morning. This will bring some scattered rain showers and isolated thunderstorms by Saturday afternoon and evening with 40-50% coverage and confidence a bit more northeast than it was Thursday. The strongest storms look to be east of the Bighorns for Johnson/Natrona Counties where CAPE values look to be more intriguing for Wyoming standards ~250-350 J/kg. Gusty outflows look to be the hazard outside of any lightning to occur and something to keep an eye on. Nothing of high significance but any rainfall will help in these areas. Regardless, once the sun sets, any lingering shower activity will weaken and exit to the east before midnight and dry out come Sunday morning.

Sunday and into next week will see a stronger upper level ridge to build in to be more oriented across the Rockies. This will bring much warmer temperatures and dry conditions for several days. Afternoon high temperatures east of the Divide look to push well into the 80s with 70s to the west. Breezy conditions will lead to elevated fire weather conditions due to the low RH values and warmer temperatures, even with greenup now ongoing for all zones. The next weather system of note looks to be by week's end late Thursday into Friday that should bring a reprieve from the warmer temperatures and increasing precipitation chances once again.

AVIATION /12Z TAFS THROUGH 12Z SATURDAY/

Issued at 430 AM MDT Fri May 8 2026

VFR conditions expected throughout the entirety of the period. Light winds and mainly clear skies to start the period with increasing high clouds in the afternoon and evening. Winds increase west of the Divide, highest at RKS up to 25kts during peak heating of the afternoon between 18-03Z. Skies continue to thicken overnight ahead of the next system for Saturday, with mid level ceilings at COD/WRL/CPR after 06-07Z. All other locations have upper level ceilings to lower into the next TAF cycle. Dry conditions expected this period with no other weather elements forecasted 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.