textproduct: Western and Central Wyoming

KEY MESSAGES

- Scattered showers early Tuesday become more widespread into the afternoon with a full changeover to snow overnight into Wednesday morning as temperatures drop.

- Winter Weather Advisories are in effect for the Green Mountains to eastern Sweetwater County due to light accumulating snow and gusty winds up to around 35 mph.

- Freeze Warnings are in effect for lower elevations east of the Divide for Wednesday morning, as low temperatures are in the 20s. - Dry and warming trend into the weekend and next week.

DISCUSSION

Issued at 200 AM MDT Tue May 5 2026

Increasing cloud cover pushing in from the north as depicted on IR. L/W trough extends with a positive tilt northeast to southwest to the upper level low across the Sierra Nevadas. This has given way to increasing divergence aloft through northern Utah to southern Wyoming as the low deepens with models having it embedded into L/W pattern. The PFJ becomes contorted across this area with much of the PVA anomaly extending across southern portions of the CWA and points east into the High Plains. As such, winter weather advisories have been added across the Green Mountains and eastern Sweetwater County for later Tuesday evening into Wednesday morning as this trough pushes northeast. Winds will be the main driver with this area seeing gusts up to 30 to 35 mph likely creating a crosswind across I-80 and Highway 287 through Jeffrey City to Muddy Gap. Likely snow amounts won't be much but expecting around 2 to 3 inches (60-70% confidence) indicative of some blowing snow to hinder visibility in these areas.

Otherwise, ongoing shower activity through southern Bighorn Basin into eastern portions of Fremont County. Models have pushed back the onset of more widespread precipitation, but CAMs are not handling this very well and thus, showing PoPs to QPF being well overdone with the NBM runs. What precipitation is ongoing looks to mix in with, or change over to, snow through sunrise Tuesday morning but not expecting an accumulation at this point in time to hinder morning commutes with temperatures still above the freezing mark. With ample cloud cover throughout the day and reinforcement of cooler air, expect temperatures to show not much of an afternoon warmup, struggling to break the 40 degree mark for many basins east of the Divide.

Better chances for precipitation changing over to snow Tuesday evening after sunset and overnight as the aforementioned upper level low becomes progressive as it passes to the south. This model shift as pulled back some QPF amounts as the more ample accumulations will be eastward and into Colorado extending to the High Plains, reaching as far as western portions of Nebraska and Kansas. Precipitation lingers into later parts of Wednesday but most activity will end as the upper trough pushes east and lifts out of the state. Wednesday morning will be the coldest of the week, with freeze warnings upgraded for many lower elevations east of the Divide.

Beyond Wednesday, expect upper level ridging to build in from the west with increasing convergence aloft. This will push the main finger of the PFJ to push northeast for the Dakotas and into the Great Lake/Missouri River Basin areas of the country. Models have backed off on this extending a bit southwest for northeastern portions of the CWA for Saturday, looking to remain at best, for far northeastern parts of the state itself. Ridging and northwest flow dominates the weather pattern for the weekend and beyond into next week with dry conditions and a warming trend in store going forward.

AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/

Issued at 430 AM MDT Tue May 5 2026

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

Showers in the vicinity at all TAF sites with low but VFR ceilings to start the period. The next round of shower activity not until after 00Z where precipitation type will be snow at that point with the colder temperatures. PROB30 groups at all TAF sites, lingering at RKS a bit longer with more activity further south. Otherwise, gusty winds with RKS the highest up to 30kts after 00Z limiting visibility further down to IFR with light snow through about 06Z. Any lingering snow will be diminishing and pushed east after this point with MVFR ceilings lingering through the end of the period. Conditions will lift to VFR into the next TAF cycle later Wednesday morning and afternoon. Mountain obscuration limited to start the period with more periods overnight into early Wednesday morning.

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

MVFR conditions at CPR/RIW/LND with light rain lingering to start the period but will improve after 14Z. A break until the next round of precipitation until after 21-22Z, where light snow will be the precipitation type due to the colder temperatures pushing in from the north. This will bring mainly MVFR conditions RIW/LND/CPR with light snow through about 06-08Z with less chances further north for COD/WRL carrying only VCSH at this time. Otherwise, slight breezes up to 18-20kts at most locations with improving conditions through the end of the period although still MVFR. Conditions improve further and lift to VFR into the next TAF cycle later Wednesday morning and afternoon. Mountain obscuration likely this morning and again this evening and through the overnight hours.

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

Freeze Warning from 1 AM to 9 AM MDT Wednesday for WYZ003>006- 010-011-017-018-020.

Winter Weather Advisory until 1 AM MDT Wednesday for WYZ009- 015.

Winter Weather Advisory from 6 PM this evening to 7 AM MDT Wednesday for WYZ019-030.