textproduct: Cheyenne

KEY MESSAGES

- Chances for scattered rain, weak thunderstorms, and snow will continue through Thursday night.

- Warmer and drier conditions are expected to return for Friday into the weekend.

SHORT TERM /THROUGH FRIDAY NIGHT/

Issued at 250 PM MDT Wed Apr 29 2026

Ongoing scattered convection seen across the region this afternoon as a weak disturbance moves across the area. While forcing is not strong, some meager instability is present with MUCAPE values around 250-400 J/kg, promoting spotty thunderstorms with this activity, but outside of the lightning, not expecting anything strong, particularly due to a a stable layer sitting just above the cloud tops at around 500mb. Moving ahead into the nighttime hours, another shortwave will dive down from the north and bring with it a cold front. This should spur the next round of precipitation for our area, with widespread rain and snow, and once again a few thunderstorms mixed in as well. With the cold air, expecting a solid patch of snow across our western zones in areas at or above 5-6000 ft. This may mix down a bit lower around sunrise and just after, and we may see some rain mixing with snow for locations east of the Laramie Range, but don't expect a return to winter if you're on the east side. Meanwhile overall QPF will remain on the low end, with around 0.2-0.35 inch for our highest peaks, which will translate to around 3-5 inches of snow, possibly up to 6 to 7 at most. The NBM is supporting this logic with only a 10-20% probability of 6+ inches in the Snowy Range, which will keep us just outside of advisory level criteria for the mountains.

Moving into Thursday evening and overnight into Friday, the aforementioned trough will continue to dive into the Great Plains and exit the region, allowing a ridge of high pressure to build into the area through Saturday morning. Some lingering precipitation, mostly for the high terrain and very light in nature, is expected through Friday morning, with skies clearing and temperatures warming as we enter a period of warmer and drier conditions. Temperatures Thursday will be in the 40's to 50's behind the cold front, rebounding into the 50's and 60's on Friday with the ridge. Unfortunately alongside this warmth we'll see moisture depart and RH values descend back into the 20's and teens on Friday. Thankfully under a weak pressure gradient, critical fire weather conditions are unlikely, but elevated concerns from the dry weather could be possible as greenup east of the I-25 corridor is limited at best currently.

LONG TERM /SATURDAY THROUGH TUESDAY/

Issued at 250 PM MDT Wed Apr 29 2026

With upper-level ridging building into Wyoming on Saturday, a pleasant and mild weekend is in store. 700 mb temperatures will climb above 0C, with temperatures as high as +7C by the the end of the weekend. Temperatures on both Saturday and Sunday will be virtually the same with highs in the 60s and 70s across southeast Wyoming and western Nebraska. These highs will be about 10 degrees above average for early May, making it a mild weekend. With the warm temperatures will also come dry conditions. The ridge will usher in a dry airmass with moisture starved low and mid-levels. This will lead to elevated fire conditions over the weekend. Luckily, there will also be little wind during this time frame with the surface high sitting just to the south in the mountains of Colorado. Therefore, this will limit any critical fire weather conditions over the weekend. The high pressure and subsidence under the ridge will also ensure that precipitation chances remain minimal with partly to mostly sunny skies.

Unsettled weather is expected to return for the beginning of the work week as the ridge weakens from a strong trough coming on shore to California. Although current long range guidance does not show any direct impacts from the upper-level low and associated trough, the CWA will be in close enough proximity to the low and trough to see near daily precipitation chances through the end of the week. Temperatures, at least through mid-week, look to hold steady in the 60s and 70s. This could help support convection, potentially severe, on both Monday and Tuesday as model soundings show almost 1000 J/kg of MUCAPE.

AVIATION /18Z TAFS THROUGH 18Z THURSDAY/

Issued at 1130 AM MDT Wed Apr 29 2026

Northwest winds with gusts around 20 kts can be expected through the afternoon hours. Widely scattered showers will develop early in the afternoon. Showers will have the potential to produce brief visibility drops, gusty and erratic winds, and a few lightning strikes. Overall coverage of precipitation today will be fairly low. Mid-level cloud cover will hold overnight as winds shift to the north or northeast. Cannot rule out low stratus around southeast Wyoming terminals late tonight that lead to MVFR/IFR CIGs.

CYS WATCHES/WARNINGS/ADVISORIES

WY...None. NE...None.