textproduct: Cheyenne

KEY MESSAGES

- Dry, warm, and breezy conditions are expected to continue through Thursday, with mild overnight lows.

- Chances for a few showers return Saturday (Halloween) with temperatures remaining mild.

- A pattern change to colder, wetter, and windier conditions is favored Sunday into Tuesday, but the details remain highly uncertain at this time.

SHORT TERM /THROUGH FRIDAY NIGHT/

Issued at 301 PM MDT Thu Oct 29 2026

Temperatures are going to be the hardest part of this short term forecast for tonight through Saturday morning. The models have indicated that a stratus deck will blanket the Nebraska Panhandle much like what has covered Sidney, Nebraska the entire day. This low stratus deck will insulate the surface, stabilizing the temperatures at some point through the night. Meanwhile most of Southeast Wyoming looks to be covered in high based clouds allowing for a little bit more cooling than what might occur in the Panhandle. So for the most part I have temperatures in the upper 30's for most of Southeast Wyoming and temperatures in the low to mid 40's for the Nebraska Panhandle area anticipating that low stratus deck to form. Patchy fog was also put into the grids as the stable atmosphere may lead to some fog production with visibility reductions as low as 1SM or possibly down to a quarter mile. High temperatures tomorrow look to be in the 50's and 60's but if the cloud layer behaves like it did over Sidney those temperatures may need to be dropped into the low 50's due to lack of diurnal heating. But no precipitation chances are expected in the short term forecast.

LONG TERM /SATURDAY THROUGH THURSDAY/

Issued at 301 PM MDT Thu Oct 29 2026

The Long term forecast is pretty complex. Saturday morning a weak shortwave that's going to push through the western portion of Wyoming giving a chance for some morning to early afternoon showers for the southwestern corner of Carbon county. Everywhere else in the forecast area will see dry conditions and temperatures in the upper 50's to low 60's. Around trick or treating time most of the area will be hovering around 45 degrees for some possible light jacket conditions with the light winds.

Sunday into early next week,

A complex storm system will push across the western CONUS Sunday into early next week. Two major players will make up this system: first, a strong, moisture-laden upper level low riding the subtropical jet stream into the southwest and second, a potent Pacific trough pushing into the northwest. The primary questions concerning the evolution of this system are if, when, and where the two approaching systems might merge together. The model guidance has a hard time resolving this event often flip flopping how cold the air aloft will be and how much forcing will be present during the next few days. Latest probabilities are a 50 percent chance for 5 inches of snow concentrated on our mountain peaks and adjacent areas above 9,000t and possibly 1-3 inches for areas like Rawlins and Laramie as they sit at roughly 7,000ft. Then for areas for along and east of the I-25 corridor the 50 percent chance is for an inch or less as it may be too warm most of the time for adequate snow accumulation. The 90th percentile which would favor colder temperatures aloft and an earlier merger has about 10 inches for our peaks, 3-5 inches for Laramie and Rawlins and 1-2 inches of snow along the I-25 corridor with trace to an inch about as far east as Kimball Nebraska. Some of the major news networks have already begun posting the clickbait potential focusing on the very upper end of the accumulation amounts. But if the air aloft stays between 3-6C instead of diving into the negatives then we are more likely to end up with a decent amount of rain and very little snow Sunday through Tuesday. The 10 percentile encompasses this scenario a little better and the snow accumulation becomes 1-2 inches for our mountain tops and a trace amount for Laramie and Rawlins. For areas along and east of I-25 the precipitation would most likely stay as rain for majority of the time and have a rain/snow mix during the heavier rain portions. The high-resolution models take their first stab at the system soon and start to resolve the system and throw their weight towards the most likely scenario.

AVIATION /06Z TAFS THROUGH 06Z SATURDAY/

Issued at 1055 PM MDT Thu Oct 29 2026

Primary Aviation concern will be low clouds and fog tonight. Southwest flow aloft will continue over southeast Wyoming and western Nebraska with intervals of mid to high clouds over the next 18 to 24 hours. Upslope flow at the surface will result in low clouds and fog over the high plains tonight through early Friday morning.

HAZARDS/WEATHER TRENDS: Fog has started a few hours early over portions of the area, mainly KCYS with VIS down to one quarter of a mile. High confidence forecast with low CIGS and fog, but low confidence on the lower VIS and timing for KCYS and all the western Nebraska terminals. Tweaked previous 00z TAFs to adjust to current trends with KCYS remaining in fog through 10z, but then lifting as winds shift slightly into the southwest after midnight. Expect CIGS across western Nebraska terminals to gradually lower through 08z, with fog developing a little later and likely after 10z for KSNY, KAIA, and possibly KBFF. KRWL and KLAR likely to stay VFR conditions due to lower surface moisture. Conditions will improve to VFR from west (KCYS) to east (KAIA and KSNY) through 18z Friday, with some IFR CIGS lingering near KSNY and KAIA past 18z.

CYS WATCHES/WARNINGS/ADVISORIES

WY...None. NE...None.