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 and Monday night, 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 TUESDAY/

Issued at 340 PM MDT Sun Apr 26 2026

The weather in the short term remains largely the same as the last few days. Scattered showers and storms during the day, with stratiform snow showers overnight. This afternoon certainly lives up to the same pattern as the previous days with clouds beginning to break up west of the Laramie Range, allowing for warming. The warmer temperatures have allowed for some scattered convective showers to develop. Some of these showers have even had a few lightning strikes! These showers will continue to push northeastward throughout the afternoon, moving into the Interstate 25 corridor and the Nebraska panhandle. Low stratus has been persistent east of the Laramie Range due to moist southeasterly flow, hence the lack of precipitation so far today. However, Hi-Res guidance has been consistent, showing showers moving into these eastern areas by the evening. Model soundings do show some instability, but not enough for severe weather. Although, cannot rule out small hail and gusty winds in storms. With the shortwave moving out of the CWA, coverage of precipitation will begin to decrease this evening. Rain will transition to snow as temperatures cool off through the night. 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 additional accumulations of 6 inches above 8500 feet.

Lingering showers will be possible Monday morning with the departing shortwave. Overall, shower activity during the morning will be fairly benign and should not cause much disruptions to Monday morning commutes. A break in showers is expected mid-day with partial clearing. This partial clearing will result in daytime heating which will lead to another round of widespread showers and storms, sparked by another incoming upper-level disturbance. Instability will once again be on the lower end so severe weather is unlikely, but small hail and gusty winds will be possible. Precipitation coverage will increase overnight as the shortwave pushes more moisture into the CWA. QPF amounts are modest with some models showing a few tenths of precipitation between Monday afternoon and Tuesday morning. Both snow and rain will be possible Monday night, but accumulations for the lower elevations look rather minor. The mountains could see over 6 inches of snowfall during this timeframe. Precipitation will taper off throughout the day Tuesday as the disturbance moves eastward into the Great Plains. However, scattered showers can be expected through much of the day.

LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/

Issued at 340 PM MDT Sun Apr 26 2026

Tuesday evening, the parent system will be pushing eastward into the Hudson Bay area. As a result the upper level trough will be pushing eastward as well giving us a brief break overnight from any precipitation chances. However, the showers are expected to resume in the afternoon Wednesday as another positively tilted trough works its way through the Rocky Mountain region. THis trough is expected to be slow moving as its parent system is a low pressure system pushing into the West coast and through the desert southwest of the United states. The lobes of vorticity slowly start to dissipate Wednesday night into Thursday morning. This is largely due to the amplified ridge pushing through the Pacific Northwest forming a Rex Block. This blocking pattern is expected to remain with the Low pressure system as it moves east preventing any Northward migration Thursday afternoon and possibly lasting until Saturday as the global models suggest the low eventually re-joining the flow and being absorbed by the Low that is fluctuating between the Hudson bay and Great lakes. During the duration of the Rex Block the Ensembles generally show the storm track being to far south to have an influence over the Southeast Wyoming and Nebraska Panhandle area. There are a couple members that bring the system a little further north so Low pops were kept as they were between 20 and 30 percent for the southern portion of our CWA through Friday evening. Friday and into the weekend looks to be predominately Upper level ridging allowing surface temps to climb back into the 60's and 70's over the weekend. After the weekend another system looks to push into the Pacific Northwest restarting this possibly wet but much needed active pattern.

AVIATION /00Z TAFS THROUGH 00Z TUESDAY/

Issued at 600 PM MDT Sun Apr 26 2026

Slow moving Pacific trough will continue to move eastward along the Colorado/Wyoming border this evening, and eventually exit the area later tonight. Stationary front will slowly lift northeast as a warm front, before pushing back south as a cold front once the Pacific trough moves east of the Front Range. Low stratus clouds, periods of rainfall, and some fog is expected to continue through Sunday night and into Monday morning.

HAZARDS/WEATHER TRENDS: Low confidence Aviation forecast for most terminals due to considerable timing differences with shower activity, potential fog, and low CIGS. Expect most locations to drop back down to IFR or LIFR CIGS between 02z and 08z. However, rain showers, and possible snow, may result in temporary higher CIGS but lower VIS at times. For now, went widespread prevailing IFR conditions for most terminals with VCSH or TEMPO showers and lower VIS for now and will reevaluate this evening. Kept fog out of the forecast due to low confidence and limited model support and mentioned BR instead.

CYS WATCHES/WARNINGS/ADVISORIES

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