textproduct: Western and Central Wyoming

KEY MESSAGES

- Tranquil and sunny days continue today and Saturday with highs in the 60s and 70s.

- An cold front will bring a low chance (20% to 30%) of showers and isolated thunderstorms to northern Wyoming Sunday afternoon, including across Yellowstone National Park.

- Cooler and unsettled Monday and Tuesday are forecast with a better chance (40% to 70%) of showers, especially across the southern half of Wyoming.

UPDATE

Issued at 1230 PM MDT Fri May 1 2026

Noon/18Z satellite imagery shows mostly sunny skies as high pressure builds in. With 700mb temperatures near 0 Celsius, expect widespread afternoon highs in the 60s Fahrenheit. The warmest area will be the Bighorn Basin, with highs right around 70 degrees Fahrenheit due to its proximity to the upper level ridge axis and warmer air aloft. With little to no clouds this evening, expect temperatures to quickly drop into the upper 40s and 50s as the sun starts setting. The upper level ridge will be directly overhead on Saturday so expect a warmer day with widespread highs in the 70s and plenty of sun. Precipitation chances are generally near zero both of these days, with mean PWATs between 0.11" to 0.25". In fact, these PWATs are below the 10th percentile of climatology. However, the higher end of that range (0.25") is forecast to be across the far northern Bighorns on Saturday. A very weak passing disturbance aloft on Saturday evening could be just enough to squeeze a light snow shower out across the far northern Bighorns (15% at best).

Otherwise, a cold front is still on track to drop across the state on Sunday afternoon and bring shower and thunderstorm chances (20% to 30%) to northern Wyoming. Most across northern Wyoming will not see any shower or thunderstorm activity as it is largely confined to the northern mountains, including Yellowstone National Park. So if you are planning to venture out into any of these areas on Sunday afternoon, remember when thunder roars, go indoors!

DISCUSSION

Issued at 1224 AM MDT Fri May 1 2026

For most of my rather lengthy career in meteorology, I have done shift work; the vast majority of it on the night shift. It has led to periods when I have had to work while very tired and sleepy. However, it can also lead to bursts of creativity and unlocking memories from years ago. And I have unlocked a core memory tonight, and it will relate to the weather over the next two days. In a time long ago (in January of the year 2000, when I was much younger and thinner), one of the cable channels that used to play music videos had a several month marathon of all the music videos they ever played in alphabetical order. And the very first video played was by a British Rock Band called 3 Colours Red, who were most popular in the late 90s. And the song in question was "(A) Beautiful Day." (Don't ask how I remembered this).

Most of the showers from yesterday have ended. There could be some leftover low clouds and patchy fog from the showers last evening, but the strong May sun should burn off fairly quickly. All in all, today looks like a very nice, dare I say beautiful early May day as high pressure builds into the area. A day when it will be crisp and cool in the morning with mild, seasonal temperatures in the afternoon, accompanied by sunshine and some clouds. The only very small fly in the ointment is the very small chance of an afternoon shower in the mountains, but with the chance only around 1 out of 10, we kept the forecast dry. Wind should remain light to moderate. Saturday also looks like a beautiful day for most. Temperatures will average 6 to 10 degrees warmer as flow turns west to southwesterly with a continuation of light to moderate winds and mainly dry conditions. Again, the only small concern is the 1 out of 10 chance of a mountain shower, mainly in the Bighorn range.

Things turn more active again on Sunday. A cold front will drop southward out of Montana and into northern Wyoming. This will bring more clouds along with a few showers and thunderstorms. The front does not have a lot of moisture to work with though. No location has more than a 2 out of 5 chance of a tenth of an inch of QPF from Sunday morning through Sunday night. And the current forecast is likely the wettest it would be. The southern half of Wyoming should have a dry and warm finish to the weekend.

At this point, Monday and Tuesday look like the wettest of the forecast period. The front will push southward and interact with moisture associated with an upper level low moving out of the Great Basin. Recent model trends have the low further south as northerly flow behind the front dominates. Moisture will over run to the front and the cooler air behind the front and bring some precipitation. Most guidance keeps this confined to southern Wyoming and areas West of the Divide though. There has been poor run to run consistency though, and confidence on the northern extent of the precipitation remains low. Nevertheless, both of these days days look cloudier and cool, with near to somewhat below temperatures across much of the area.

From Wednesday into the end of the week, ridging should bring a return to warmer temperatures. The eastward extent is still up to question though. If it is further east, the pattern will be warm and largely dry. If it is further west, Wyoming will be on the edge of it and some shortwaves moving southeastward around the edge could bring some showery episodes late in the week. Still uncertain which it will be at this time though.

AVIATION /18Z TAFS THROUGH 18Z SATURDAY/

Issued at 1105 AM MDT Fri May 1 2026

Prevailing VFR conditions through the TAF period. High pressure will keep it warm, dry, and mostly clear for the next 24 hours. Generally, wind will be light 10 knots and less.

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.