textproduct: Western and Central Wyoming

KEY MESSAGES

- Steady precipitation ends early today. Otherwise, expect another cool day with scattered showers, especially across southern Wyoming.

- High pressure brings two nice days Friday and Saturday with mild to warm temperatures and a good deal of sunshine.

- The chance of showers returns on Sunday across northern Wyoming, with a more widespread chance of showers Monday night into Tuesday.

DISCUSSION

Issued at 305 AM MDT Thu Apr 30 2026

As I write this discussion around 2 am, the Wind River Basin and Lander Foothills are getting some well needed moisture, in the form of both rain and snow from a weak 700 millibar circulation that is bringing some northerly upslope flow to the area. Any accumulations would mainly be around Lander, although as of 2:30 am there is only a small coating on the grass. There will likely be an inch or so in Lander, with higher amounts as you head toward Sinks Canyon, again largely on non paved surfaces. Almost all guidance shows the majority of the precipitation ending by sunrise. All in all, today looks fairly similar to yesterday with another shortwave passing through the area, bringing another round of scattered showers and isolated thunder. Coverage looks slightly less than yesterday, and more concentrated in southern portions of the state where the shortwave will be in the afternoon. Showers should taper off after sunset.

Ridging should then build over the area for Friday and Saturday, and bring a couple of nice Spring days. Friday will start off chilly but plenty of sunshine and seasonably mild temperatures will bring a nice afternoon. Saturday looks even nicer as flow turns more west to southwesterly bringing warmer temperatures while maintaining sunshine. In addition, wind should remain light to moderate, a luxury this time of year. If you can, get out and enjoy both of these days.

Climatologically, May is the wettest month of the year. And, the chance of showers and thunderstorms may return to the area on Sunday as a cold front drops toward the area on Sunday. Most guidance shows the main impacts across northern Wyoming with this front. However, most of this day looks largely dry and warm across a majority of the area, especially across southern portions of the state.

Cooler temperatures return behind the front Monday. Then we get another chance of more widespread precipitation Monday night and into Tuesday as an upper level low moves toward the area from the West Coast and passes south of Wyoming. The NBM ensemble guidance gives a greater than 1 in 2 chance of greater than a quarter of an inch of QPF across the favored north to northeasterly upslope locations from Lander to Casper from Monday night to Tuesday night. This is still uncertain though as deterministic models have differences of a few hundred miles with the position of the low, impacting placement of the heaviest precipitation. And with the increased cloud cover, temperatures will again be below normal on Tuesday. Following this, ridging builds back over the area. There are uncertainties with precipitation as some guidance has Wyoming on the eastern edge of the ridge so shortwaves could bring showers for the end of the week while other are dry. However, most guidance shows a return to above normal temperatures by next Thursday.

AVIATION /12Z TAFS THROUGH 12Z FRIDAY/

Issued at 512 AM MDT Thu Apr 30 2026

Areas of overnight showers are shifting southward this morning, with only impacts expected at KLND and KRKS through around 16Z. There is a very low chance (20%) of showers again this afternoon at KPNA off the Wind River range to the north. Shower chances are still a low possibility at KBPI/KPNA (~10%), but not widespread enough to note in TAFs. As this system settles southward, gradually clearing skies are expected across the state, with VFR conditions through the afternoon and overnight tonight.

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.