textproduct: Cheyenne

KEY MESSAGES

- A Red Flag Warning is in effect for the I-80 corridor from Cheyenne to Sidney this afternoon due to low humidity and breezy conditions.

- Isolated to scattered showers and snow showers possible this afternoon and evening due to a stationary front draped across the region.

- Easterly, upslope flow develops Saturday, leading to increasing precipitation chances for much of the region.

- Relatively cool and wet weather is expected for the weekend and early next week.

SHORT TERM /THROUGH SATURDAY NIGHT/

Issued at 211 AM MDT Fri Apr 24 2026

Upper-level trough remains in place across the region today as the broad, upper-level trough spins over southern Canada. Poor vorticity advection at 500mb will prevent this trough from quickly moving off to the east, therefore, cooler and cloudier weather will continue. With the upper-level system struggling to push eastwards, the 700mb low will continue to spin across southern Canada with a few North/South meandering throughout the day. Therefore, elevated height gradients are anticipated to remain across the CWA, favoring breezy conditions for another day. The 700mb low will stay largely north enough to prevent a very strong 700mb jet from developing, but the jet is anticipated to peak around 45kts. With modest downward omega values progged by the GFS, breezy conditions are expected to develop across western portions of the CWA throughout the day today. With the weaker 700mb jet, high winds are not expected, but gusts over 40 mph cannot be ruled out at this time. Near the surface, a stationary front looks to develop as the 700mb low continues to spin in one location. As a result, ongoing precipitation development along the front is expected, though widespread precipitation is not anticipated at this time. Precipitation chances range between about 20 to 45%, with the highest values in northern portions of the CWA where better ascent may develop. Increasing cloud cover this afternoon combined with the stationary front draped across the region will lead to a cooler day, with widespread high temperatures. Northern portions of the region will see temperatures peaking in the mid-40s, while all other locations with see 50s and 60s, depending on exactly where the stationary front sets up this afternoon. Right now, the front is expected to setup along a line from about Douglas to Wheatland to Sidney. As a result, many locations along Interstate 80 from Cheyenne to Sidney will see significant drying this afternoon, with humidity values dropping to the 10-15% range and winds gusting up to 35 mph. Red Flag Warnings remain in effect for this area through 8 PM tonight. As precipitation slowly migrates southerly, Red Flag conditions are expected to improve with the increasing moisture.

Saturday looks to be a little more active as upper-level propagation begins to pick up as another upper-level trough moves onshore in southern California. Multiple vorticity maxima will eject out ahead of the incoming trough, resulting in synoptic ascent across the region and a shortwave trough developing at 500mb and ejecting through the region southwest to northeast. 700mb flow remains mostly southerly across the region Saturday as a 700mb shortwave propagates southeast of the CWA. Luckily, with largely southerly flow in the lower-levels, increasing moisture is expected across the region. Additionally, a backdoor cold front will push into the region from the east, leading to largely easterly, upslope flow along and east of the Laramie Range. Precipitation chances will increase into the 60-70% range Saturday night. Mostly rain is likely east of the Laramie Range where temperatures will be a touch warmer overnight Saturday, with rain/snow then snow expected west of the Laramie Range where temperatures will be cooler. Upslope flow will continue for much of the day and into the overnight hours. Total precipitation accumulation looks to be quite decent at this time, potentially the most precipitation we have seen in a while. However, it will still be nowhere near enough to put a dent in the drought. Luckily, an active pattern is expected to continue into the long term forecast.

LONG TERM /SUNDAY THROUGH THURSDAY/

Issued at 211 AM MDT Fri Apr 24 2026

A mid level disturbance is expected to make its presence known on Sunday as it moves in from Southern California. At the surface we should be behind a cold front with temperatures in the 30s and 40s over much of the area. A warm nose around the 650 mb layer will promote rising motions above the shallow cool layer and a saturated profile will increase our rain/snow chances. Cyclogenesis is expected to our south and will keep the cold air advection going through the day. So, expect cool and wet conditions in other words. The Snowy and Sierra Madre ranges may pick up 2-4 inches of snow. Most of the are around 0.15-0.25" and perhaps higher amounts in the southern Nebraska Panhandle where some lucky spots could receive a half inch in rainfall. This system departs to the northeast quickly overnight. Periods of snow showers may continue through the morning hours as temperatures hover around the freezing level over much of the area. We keep this seasonable weather trend going into Monday, which may end up slightly cooler than Sunday. Chances of precip do decrease during the day, but we get another round of increased PoPs in the overnight hours as another upper level vorticity maximum passes over the area, courtesy of the trough that's been in place over Canada since last Thursday. We may pick up another tenth of an inch of rainfall with this disturbance and the mountain ranges another 2 inches or so of snow. We will gladly take what we can get to improve our current dry conditions and buffer ourselves from the next drying spell. Winds may also increase as this shortwave moves through Tuesday. Presently there are no concerns of high winds. Persistent troughing seems to be a more favored outcome going into Wednesday and to end out the forecast period. Therefore, expect generally cool and wet conditions.

AVIATION /12Z TAFS THROUGH 12Z SATURDAY/

Issued at 538 AM MDT Fri Apr 24 2026

KCDR continues to experience MVFR to IFR conditions as lingering areas of rain and snow showers. These showers are expected to last for the next few hours. Breezy winds are expected to begin in the mountains in the next few hours. KRWL, KLAR, and KCYS could recieve gusts up to 45 kts from the west. Another cold front is anticipated to move southeast through the day. A shift in winds of about 30-35 kts from the north and lower ceilings at terminals can be expected. Ahead of the front, at the NE Panhandle terminals, showers are likely starting around 19z and persisting through at least 23z. Showers may lingering a few hours beyond then. Ceilings will continue to lower through the overnight hours, likely to reach MVFR conditions, and winds become light and variable at most terminals. Some patchy fog may occur at KBFF, KCDR, SNY, and KAIA late in the forecast period.

CYS WATCHES/WARNINGS/ADVISORIES

WY...Red Flag Warning from noon today to 8 PM MDT this evening for WYZ430-431. NE...Red Flag Warning from noon today to 8 PM MDT this evening for NEZ437.