textproduct: Cheyenne

KEY MESSAGES

- A messy pattern is anticipated today through much of the upcoming week, allowing for ongoing precipitation chances across the entire CWA. The best chance for precipitation will be Sunday, with widespread showers and thunder.

- A Winter Weather Advisory has been issued for the Sierra Madre and Snowy Ranges from 6PM Saturday through 6AM Monday.

SHORT TERM /THROUGH SUNDAY NIGHT/

Issued at 346 PM MDT Sat Apr 25 2026

Radar is picking up on light showers in the western portion of the CWA where clear skies have lead to warming and the development of a cumulus field. Showers are originating out of this cumulus field, however it does not appear that much, if any precipitation is reaching the ground due to the dry low-levels. This shower activity will continue through the evening hours per Hi-Res guidance and should mainly stay along and west of the Interstate 25 corridor where there is cleaning. The Nebraska panhandle remains rather stable this afternoon with cooler temperatures due to a persistent low stratus deck. As a result, went ahead and nudged high temperatures down into the 40s for the Nebraska panhandle for the remainder of the afternoon. Cannot rule out a stray shower overnight as sufficient low-level moisture moves into the area, however, instability and forcing will likely limit their development.

Precipitation will become more widespread Sunday morning as the next shortwave moves into Wyoming. Precipitation during the morning hours will be more stratiform in nature given the stable environment. After some warming and partial clearing, a secondary round of precipitation is expected that will be more convective. Hi-Res guidance shows widespread showers and thunderstorms developing off the high terrain and pushing northeast through the afternoon. Both PWATs and IVT values are in the 90th percentile for NAEFS climatology so a wet day with ample moisture is expected. Although showers will be scattered in nature, it is likely that all locations see some type of precipitation either Sunday or Sunday night. Thunder will also be possible in both rain and snow showers throughout the day tomorrow as a few hundred joules of CAPE exist. There is not a strong signal for severe storms, however because this is Wyoming and the high plains, cannot rule out rogue gusts to 60 MPH or small hail. Showers will return to a more stratiform state once again Sunday night. With the shortwave moving out of the CWA, coverage of precipitation will be lower overnight. Rain will transition to snow as temperatures cool off through the evening. Lower elevation snow accumulations will be possible, but will generally be below an inch with most places expected to see a dusting. The Snowy and Sierra Madre Ranges will be the exception to this with Winter Weather Advisories in place for accumulations of 6 to 12 inches above 8500 feet. Snow will gradually taper off through Monday morning as the shortwave moves out of the area.

LONG TERM /MONDAY THROUGH SATURDAY/

Issued at 346 PM MDT Sat Apr 25 2026

A departing upper level trough will be pushing into the Northern Plains monday morning. There may be some lingering showers in the Panhandle that will pushing east through the morning. A weak transient ridge will push through the Intermountain West giving us a temporary pause in the showers Monday afternoon. This break will be short-lived as another shortwave will be moving into the Intermountain West by Monday evening. The global models roughly agree on the timing with this shortwave as well but start to disagree on the strength of shortwave. The GFS wants to start to close off the shortwave indicating a stronger system but the Canadian and Euro maintain it as an open wave to suggest a potentially weaker system migrating through the Rockies. There looks to be sufficient moisture as our cooler temperatures will help maintain a borderline saturated environment during the work week. This upcoming week will remain pretty active with multiple shortwaves throughout the week. Each wave or system looks to have vortmaxes accompanying them to add in the synoptic lift and give the region some much needed rain chances. 700mb temperatures range from - 3C to +1C keeping temperatures around 40 to 50 degrees during the day and dropping into the 30's at night bring for a slight chance for some rain transitioning to snow during the overnight hours into the following early morning. Outside the Sierra Madre, Snowy, and Northern Laramie ranges, total snow accumulations look to be less than an inch with measurable accumulations on the mountain peaks and possibly some light accumulation in the foothills between Laramie in Cheyenne as the models do hint to some possibly enhanced snowfall due to mesoscale forcing in that area. The vast majority of the counties along and east of the I-25 should expect most of the precipitation to come down as rain with non accumulating (trace) amounts of snowfall if showers occur overnight.

AVIATION /00Z TAFS THROUGH 00Z MONDAY/

Issued at 550 PM MDT Sat Apr 25 2026

A stationary front will remain near the Colorado and Wyoming border tonight before lifting northeast slowly as a warm front ahead of the next Pacific upper level disturbance. This upper level trough will movee eastward into Utah and Wyoming by Sunday morning. Widespread low CIGS, periods of rain and snow, and some fog possible in between bands of showers through Sunday afternoon.

HAZARDS/WEATHER TRENDS: MVFR CIGS will continue for most terminals as we head into tonight with models trending towards IFR CIGS between 06z and 12z for all eastern plains terminals and continuing through Sunday afternoon for some locations. Expect upslope winds to continue with east to southeast winds occasionally gusty tonight. Bands of rainfall (snow above 6500 feet) will develop during the TAF period, with the main band developing along the surface warm front by 12z Sunday. May see periods of IFR VIS, especially around KRWL, KLAR, and KCYS, where some snowfall is likely. Dense fog is possible around KCYS between 09z and 15z, but confidence is only around 20% at this time, so will mention VCFG fog now.

CYS WATCHES/WARNINGS/ADVISORIES

WY...Winter Weather Advisory until 6 AM MDT Monday for WYZ112-114. NE...None.