textproduct: Cheyenne

KEY MESSAGES

- A cold front moved through overnight and is expected to bring cooler temperatures and a chance for widespread rain and snow showers Tuesday through Wednesday night.

- Accumulating snow is expected for the higher mountains above 9000 ft in elevation Tuesday night through Wednesday evening.

- Isolated to scattered showers and potentially thunderstorms are possible Wednesday afternoon. Severe weather is not expected at this time.

- After a brief warmup Thursday, another strong cold front will sweep through the area and bring another round of rain and snow Thursday afternoon into Friday.

SHORT TERM /THROUGH WEDNESDAY NIGHT/

Issued at 101 AM MDT Tue Mar 31 2026

The cold front is slowly moving across the region tonight and is currently just north of Cheyenne eastward to just north of Bridgeport. The front is expected to exit the region within the next 1 to 3 hours, leading to gusty northerly winds in its wake. Minimal to no precipitation is ongoing across the area as a result of the frontal passage, but isolated showers cannot be completely ruled out overnight. Upper-level flow turns largely zonal later this morning into the afternoon, allowing the more mild temperatures to continue across the region, especially as 700mb temperatures drop into the 0 to 2C range this morning throughout the day. Precipitation is expected to be scarce outside of the higher elevations, despite the frontal passage, as the best synoptic support does not move into the area until late this evening into the overnight hours tonight. 700mb flow is progged to turn southwesterly across western portions of the region, leading to favorable wind direction for continued upslope development, especially along the Sierra Madres. Snow begins in the higher elevations by sunrise and will continue through the next couple of days. As for the rest of the region, expect cooler temperatures today with highs in the mid-40s to mid-50s east of the Laramie range and mid-50s to low-60s west of the Laramie Range where 700mb temperatures are expected to quickly rebound.

Later this evening, an upper-level shortwave trough will push towards the region, with synoptic lift out ahead of the trough beginning as early as midnight tonight. Modest 500mb cyclonic vorticity advection is expected late tonight into the early morning hours Wednesday, allowing the upper-level trough to propagate eastward, though at a slower rate due to magnitude of the CVA. The trough axis is expected to be across the Nevada/Utah state line by 12Z Wednesday morning. A diffuse 700mb shortwave develops late tonight into early Wednesday morning with southwesterly flow increasing across western portions of the CWA. Beginning by 00Z Wednesday, a messy, surface low attempts to organize over western Wyoming, further supporting the development of southwesterly flow at both the surface and 700mb across the higher elevations with more southeasterly flow expected east of the Laramie Range. Both east and west of the Laramie Range will see fairly favorable surface flow to support upslope development, so precipitation is expected to become more widespread late tonight into Wednesday morning. This period from about midnight tonight through noon Wednesday will see the highest snowfall rates across the higher elevations out west, given strong southwesterly flow throughout the atmosphere and NAEFS Mean Integrated Water Vapor Transport suggesting values in the 90th percentile for this time of year with precipitation water peaking above the 97.5th percentile for the same area and time. Much of the 6 to 12 inches of snow forecast for the Winter Weather Advisory is expected to fall during this time before slowing tapering off Wednesday afternoon/evening.

Wednesday morning and afternoon will see the best chances for widespread precipitation across the lower elevations. As Colorado Low is progged to develop in east central Colorado Wednesday morning into the early afternoon hours and advect due east through Thursday morning. This track is favorable for much of the CWA to see easterly, upslope flow throughout the afternoon Wednesday, with flow turning northerly by Wednesday evening. If this were a more typical winter, the CWA would be expecting some decent snowfall totals from this system, however, it is anything but a typical year for southeast Wyoming and western Nebraska. Therefore, 700mb temperatures are expected to remain quite warm throughout the day Wednesday before slowly dropping off Wednesday after sunset. Much of the precipitation with this system is expected to fall as rain, with a few isolated thunderstorms possible across areas east of the Laramie Range. Severe weather is not expected at this time as instability remains too low for severe, but high enough for isolated thunder and lightning. The Storm Prediction Center is highlighting the region in a General Thunder threat for Wednesday. Snow is only really expected in the highest elevations and potentially far western portions of the CWA. Despite this, beneficial rainfall is expected across most areas with the Wednesday system, though it will hardly put a dent in the ongoing drought across much of the western CONUS.

LONG TERM /THURSDAY THROUGH MONDAY/

Issued at 101 AM MDT Tue Mar 31 2026

No major changes. Please see previous discussion for more details...

A potent upper-level trough will come ashore the west coast on Thursday and quickly make its way eastward throughout the day. This trough will bring precipitation chances to the CWA for the end of the work week. By Thursday night, the trough will enter the western reaches of the CWA, with precipitation creeping into Carbon and Albany Counties as early as Thursday afternoon. The cold front associated with this trough will be rather strong, advecting much colder air into the region very quickly. While precipitation may start as rain Thursday afternoon, it may quickly change to snow with the frontal passage. This raises concerns for snow squall potential as there will be minor instability out west with blustery conditions from a strong MSLP gradient. A flash freeze behind the front is also in question depending how quickly temperatures drop and when precipitation arrives. Snow will likely continue into the overnight hours for areas west of the Laramie Range with some accumulation possible for the lower elevations.

Models begin to differ Friday with how to handle the upper-level closed low associated with the trough. The GFS has a more northerly track along the Wyoming/Montana border while the ECMWF takes a more southerly track along the Colorado/Wyoming border. The more northerly solution of the GFS is dryer, keeping most of the precipitation in the northern zones of the CWA. The more southerly track of the ECMWF brings the precipitation a bit farther south in the North Platte River Valley, but still mostly keeps the Interstate 80 corridor east of Cheyenne rather dry. Regardless of which solution comes to fruition, both have much colder high temperatures on Friday behind the front. Highs will mainly be in the 30s and 40s, with 50s possible in the southern Nebraska panhandle. These colder temperatures means precipitation could fall as snow, or at least a rain/snow mix. At this time, cannot rule out some lower elevation accumulations for areas east of the Laramie Range, but for now, the most confidence in accumulation remains in the high terrain.

Once the trough moves out of the region, a return to warmer and drier conditions can be expected as upper-level ridging takes its place. Cold air aloft will still be in place Saturday, so the return to above average temperatures will happen on Sunday with highs in the 50s and upper 60s.

AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/

Issued at 1103 PM MDT Mon Mar 30 2026

A cold front will dive south across the CWA tonight followed by a weak warm front pushing through Tuesday afternoon. Both of these will bring increased chances of precipitation and lower CIGs. Confidence is lower with the system initially, so kept PROB30 groups to account for this into Tuesday afternoon. By 00Z Wednesday, confidence increases in the timing and coverage of precipitation and as a result, expect MVFR conditions to impact all terminals at varying times sometime around 00Z Wednesday and after with CIGs less than 5K feet and VIS around 4SM in -RA. In addition, with these two fronts, expect wind shift from the north to south by Tuesday afternoon with gusts 25 to 35 knots.

CYS WATCHES/WARNINGS/ADVISORIES

WY...Winter Weather Advisory from 6 PM this evening to 9 PM MDT Wednesday for WYZ112-114. NE...None.