textproduct: Western and Central Wyoming

KEY MESSAGES

- Remaining unsettled today with a scattering of rain and snow showers.

- Below normal temperatures and chances for showers continue from Tuesday through Thursday, although details in placement and amounts of precipitation remain uncertain.

- Dry and warmer weather returns for Friday and Saturday.

DISCUSSION

Issued at 242 AM MDT Mon Apr 27 2026

Most of the winter and early spring has been rather mild, with little snow. However, it has been my luck that I have had to drive to work in the three worst periods to drive, including this evening. Visibility was rather low in blowing snow. As I write this around midnight, we are on the back edge of the heaviest snow in Riverton, but some light snow will linger for much of the night before ending from west to east through the morning. As for the advisory across the Bighorns and northern Johnson County, it is currently still snowing and we will let it go for now. We could end up canceling it early. The football draft was this weekend. So, in association with football injury reports, whether or not to cancel it will be a game time decision. Additional accumulations after sunrise should remain light, generally less than a 1 in 4 chance of an inch or more except across the higher elevations. In addition, much of the snow will melt off today as the strong late April sun crosses the sky. And for your information, solar irradiance is on average now almost 3 times as strong as it is in December around the winter solstice.

Another wave, this one also of southern origin will approach the area this afternoon. Most model guidance keeps the precipitation largely across the southern half of the area with the heaviest precipitation remaining to the south and east of our county warning area. The chances of an inch of snow are less than 1 out of 2 in all locations. Snow showers will continue across the northwestern mountains as well, but again, amounts should remain on the light side. The only place with greater than a 1 in 2 chance of 3 inches or more is in northern Absarokas and here there are basically no roads and few impacts. So, no further highlights will be issued.

Unsettled weather will continue across the area through at least Wednesday and possibly Thursday. A series of shortwaves will continue to move through a longwave trough in place across Wyoming, bringing some rounds of showers through this period. One looks to move through on Tuesday and another on Wednesday, with the one on Wednesday looking a bit more potent. The models continue to have disagreements on placement of the showers and heaviest precipitation though. So for now, we kept POPs generally broadbrushed through the period. With the trough in place and ample cloud cover, temperatures should remain below normal through Thursday.

Ridging should then build over the area for Friday and Saturday, bringing a return to dry conditions and near to above normal temperatures. Another front may approach the area for the end of the weekend with the next chance of showers, but details are still uncertain, as they usually are this far out.

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/

Issued at 1058 AM MDT Mon Apr 27 2026

Low clouds have remained persistent for KCPR and KCOD this morning, but will finally lift to VFR levels in the next hour or so. The next weak wave moves across southern WY late this afternoon and evening. This will bring a low chance for showers to KBPI/KPNA/KJAC through around sunset, and a better chance for showers with a possible clap of thunder at KRKS late this afternoon. This precip pivots into KCPR around 00Z and will continue through around 12Z Tuesday, with MVFR to IFR cigs and light snow through the night. KCOD/KRIW/KLND may be on the very fringes of the precip, and any precip will have a low and brief impact on those airports either side of 00Z. Once hit s system sweeps east early Tuesday morning, skies will gradually thin from east to west, with VFR conditions dominating the day.

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.