textproduct: Cheyenne

KEY MESSAGES

- A complex but disorganized storm system will move into the area Sunday, bringing multiple rounds of rain and snow showers through Tuesday morning.

- Winter Weather Advisories are in place for the mountains as well as the Arlington area and South Laramie Range. Accumulating heavy, wet snow is possible in these areas.

- Widespread windy conditions are anticipated Monday and Monday night.

SHORT TERM /THROUGH TUESDAY/

Issued at 324 PM MST Sun Nov 1 2026

Currently looking at a dreary day across most of the forecast area. A blanket of cloud cover sits over the CWA with patchy fog dotting southeast Wyoming and the Nebraska panhandle. Radar does show some light echoes as well, however its hard to confirm whether or not any precipitation is currently making it to the ground. Temperatures are a bit cooler than anticipated, mainly due to the thick cloud cover and lingering fog. But, warm air advection still persists with moist southerly flow keeping 700 mb temperatures on the mild side. Precipitation coverage will increase this evening and overnight, but will likely still be on the spotty side until the system becomes more organized. The cold front will arrive Sunday night, gradually ushering in cooler air. Simultaneously, leeside cyclogenesis will be occurring in northeast Colorado, forming a surface low. Cluster analysis from both the GEFS and ECMWF ensemble are still in good agreement regarding surface low placement and track into the day Monday. A majority of the precipitation that falls overnight will be rain as cooler air slowly fills in behind the front. The exception to this, of course, will be the mountains. Winter Weather Advisories are in place for the Snowy and Sierra Madre Range starting tonight. Snow will begin later this evening and continue through the day Monday. At the end of the event, locations above 9000 feet will likely pick up between 6 and 12 inches.

A colder day is expected Monday behind the front with temperatures in the 30s and 40s for southeast Wyoming and low 50s for the Nebraska panhandle. As a result, snow could begin to mix with rain as snow levels drop to about 5500 feet. The mix and potential full change-over to snow could happen as early as Monday morning for locations along and west of the Laramie Range. PWATs are at climatological max per NAEFS and more closely resemble that of a summer monsoon event! As a result, expect fairly good precipitation rates, especially with Hi-Res guidance showing steady and widespread precipitation once the CWA enters the wrap around moisture regime of the surface low ejecting into Nebraska. Higher precipitation rates could lead to a quicker change over to snow, and thus the potential for higher snowfall accumulations. The mountains and higher elevations are still the areas with the highest confidence in seeing accumulations. Winter Weather Advisories are also in effect for the North Laramie Range, whose northern slopes could see between 6 and 12 inches from upslope flow, and the Arlington area and South Laramie Range. These higher elevation spots along Interstate 80 could pick up roughly 2 to 4 inches of heavy wet snow given the temperatures and PWATs. This could lead to difficult travel at times. Areas outside of the aforementioned locations west of the Laramie Range could also see accumulating snow ranging anywhere from a trace to 2 inches. Snow amounts are a bit more uncertain east of the Laramie Range as the transition may or may not happen later in the day. Hi-Res guidance shows steady precipitation in this area during the afternoon and into the evening hours. Places like Cheyenne and Douglas could see some minor accumulations, but even this is uncertain. Ensemble guidance from both the GFS and ECMWF show very few members with even light accumulations for these cities. The other area to watch will be the Pine Ridge. The HRRR is really latching onto the upslope flow and nails the Pine Ridge between Lusk and Chadron with fairly high accumulations. This is even more uncertain, but lingering precipitation Monday night combined with the north winds could lead to quickly accumulating snow.

The other issue Monday will be the strong winds. As the surface low ejects into Nebraska, a strong MSLP gradient will set up on the eastern plains. Hi-Res guidance like the HRRR suggests marginally high winds east of the Laramie with gusts up to 60 MPH. However, given a lack of any decent subsidence, its hard to rationalize that widespread 60 MPH winds will materialize Monday afternoon into Monday evening. Even NBM probabilities of wind gusts >48 kts are on the low side across the plains. For now, held off on any high wind headlines to allow for a few model cycles to see if there is greater confidence in wind gusts. Regardless, it will be windy on Monday, with frequent gusts of 50 to 55 MPH. These blustery conditions will continue into Tuesday morning, before weakening during the afternoon hours.

The weather on Tuesday looks quieter as the surface low pushes further off to the northeast. Some lingering precipitation and wind will still be present in the Nebraska panhandle during the morning hours, but will taper off by the afternoon. Decreasing clouds are expected throughout the day with mostly sunny skies anticipated by the afternoon. Upper-level ridging will quickly move in behind the storm system, leading to warmer temperatures as 700 mb temperatures rise back into the single digits. Highs in the 40s and 50s are likely, however, could be cooler based on amount of snow cover.

LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/

Issued at 342 PM MST Sun Nov 1 2026

As we start off the long term period, lets take a quick look at the synoptic setup, we have a deep trough draped south across the Central Plains, just to our east, while ridging builds in from the west. This ridge will keep us in a dry northerly to northeasterly flow regime across our CWA with plentiful sunshine making a triumphant return. As we progress into Wednesday, weak ridging is in place overhead while model consensus has another cut-off low diving southeast from Idaho. This feature will bring an increase chance of precipitation primarily across the Sierra Madre and Snowy Ranges. Where at the higher elevations could get and inch or two of fresh snow. Otherwise, for the remainder of the CWA, this system will not have any impacts elsewhere as it continues to dive southeast across the Four Corners region through Wednesday. Quickly behind it, ridging nudges back in late Wednesday into Thursday. By the tail end of the week into next weekend, there are some differences in model solutions with the placement and amplitude of synoptic features. With the ECMWF having a deep trough just to our east while the GFS has the trough slightly further east over the Great Lakes. However, most model solutions have a ridge in place over our region with dry northwesterly flow. With all that being said, stay tuned to the forecast for future updates.

Now, switching gears and taking a closer look at temperatures for the long term period, expect highs to climb into the mid to upper 40s, possibly a few location topping out in the lower 50s, west of I- 25. While temperatures will soar into the lower to mid 50s east of I- 25 for the remainder of the work week into the weekend. In general, expect lows to dip into the lower to mid 30s across the CWA, possibly slightly colder west of the I-25 corridor.

AVIATION /00Z TAFS THROUGH 00Z TUESDAY/

Issued at 443 PM MST Sun Nov 1 2026

Several forms of adverse aviation weather will be attendant with this complex system. Current regional radar and satellite data is showing widespread low level cloud coverage with light shower activity. KSNY and KAIA are already beginning to experience reduced visibility and lower CIGs. These low CIGs and VIS are expected to continue to spread east and northward. The dry slot of the upper level system should switch winds out of the west and dry up the surface enough to bat back these low VIS and CIGs after about 06Z. Scattered showers and thunderstorms form from about KBFF to KCDR with some chances of thunderstorms impacting KAIA and KSNY. A strong cold front pushes southeast after 08Z with gusts reaching 45 knots or higher after its passage. Light to moderate rain is expected to impact most terminals after the cold front and on the west side of the system. KRWL and KLAR have a risk of rain switching over to snow. There is a low probability that the snow accumulates on tarmac surfaces, given marginal overnight lows. However, the snow rate may be high enough for this to occur regardless. Reduced VIS and CIGs are anticipated again with this shower activity through the end of the forecast period.

CYS WATCHES/WARNINGS/ADVISORIES

WY...Winter Weather Advisory from 5 AM to 11 PM MST Monday for WYZ103. Winter Weather Advisory from 5 AM to 5 PM MST Monday for WYZ110. Winter Weather Advisory from 11 PM this evening to 11 PM MST Monday for WYZ112-114. Winter Weather Advisory from 11 AM to 11 PM MST Monday for WYZ116. NE...None.