textproduct: Cheyenne

KEY MESSAGES

- Chances of precipitation increase over the weekend for the mountains, with a few spotty showers possible mainly along and south of the I-80 corridor.

- A more active pattern is expected into the middle of next week, with precipitation chances returning Wednesday into Thursday.

SHORT TERM /THROUGH SUNDAY NIGHT/

Issued at 200 AM MST Sat Nov 14 2026

Surface observations and 10.3-3.9 um IR Satellite loop shows another round of low clouds and areas of fog early this morning, this time with higher areal coverage compared to last night. Fog and lower visibility seems to be more confined near the I-25 corridor on the lee-side of the Laramie Range, and across the Cheyenne Ridge extending into Kimball Nebraska. Dense fog has been brief and limited to the lower valleys, but will continue to monitor the areal extent as we head into the early morning hours in the event we need a Dense Fog Advisory. Otherwise, not many changes to the weekend forecast as the next Pacific storm system, currently moving eastward over the Great Basin Region, is expected to stay south of the Wyoming/Colorado border today. In fact, models have trended even further south with this system as of the 00z model runs with high res ensembles (REFS) and the HRRR showing hardly any precipitation at all outside the mountains today and this evening. Given this trend, decreased POP a bit along the I-80 corridor with POP near 50 percent across the mountains for maybe an inch or two of snow above 9000 feet. Cooler today with ample cloud cover and upslope south to southeast winds. Highs will struggle to reach the 50s and will generally top out in the mid 40s to mid 50s through this afternoon. There is some uncertainty with today's high temperatures as low clouds and even some patchy fog may linger into the afternoon hours. This may keep high temperatures in the low 40s for a few places across far eastern Wyoming and western Nebraska. Also, low clouds and fog may return to the high plains, after a brief break, later tonight. Fog is expected to be more patchy compared to the last few days with breezy winds near the surface.

For Sunday, models show the Great Basin storm system ejecting south and east into Texas and Oklahoma by Sunday morning. Lingering morning cloud cover should give way to mostly sunny skies by noon-ish with high temperatures trending back into the 50s to low 60s. Shortwave ridge axis will translate eastward into the Intermountain West and northern Front Range by later on Sunday with a gradual warming trend likely into Monday.

LONG TERM /MONDAY THROUGH FRIDAY/

Issued at 1226 PM MST Fri Nov 13 2026

Monday...The unusually mild weather continues with broad southwest flow aloft, and high 500 mb heights near 5760 meters overhead. This will induce decent surface lee troughing and mild weather enthusiasts will rejoice with 700 mb temperatures near 6 Celsius and downslope warming boosting maximum temperatures into the mid 50s to mid 60s.

Tuesday...Stronger southwest flow aloft develops across our neck of the woods here in southeast Wyoming and western Nebraska, with a slightly negatively tilted shortwave trough aloft moving across Idaho, Utah and western Wyoming, with surface lee troughing keeping our weather conditions high and dry once again with slightly cooler 700 mb temperatures near 4 Celsius and slightly cooler temperatures for our forecast area, though still on the mild side.

Wednesday...The aforementioned shortwave trough aloft loses amplitude as it moves to eastern Montana and the western Dakotas by sunrise, sending its associated cold front into our counties, Pacific originated. As is typical with these systems, will see scattered to numerous rain and snow showers early in the day west of a Douglas to Laramie line due to dynamics and orographics with some decent snows across our northern Laramie, Snowy and Sierra Madre Ranges, though downslope wind east of the mountains and Laramie Range will as usual provide a rain shadow effect with little if any precipitation east of the Interstate 25 corridor and Laramie Range. Orographic snows will continue in the afternoon for our Snowy and Sierra Madre Ranges, and we may need some type of Winter Weather Highlight such as a Winter Weather Advisory, if model congruency continues.

Thursday...Looks like a windy and relatively mild day for November, the beginning of our typical windy November through March windy season. Strong southwest flow aloft continues, and our wind prone locations such as Arlington, Bordeaux and the Interstate 80 Summit between Laramie and Cheyenne may see some strong winds, and possible wind highlights.

Friday...For climatology enthusiast, November 20th is the latest first measurable snowfall event in recorded history for Cheyenne, with at least one tenth of an inch of snow measured on the ground. Interestingly, this coincides with a decent and progressive neutrally tilted shortwave trough aloft that is progged to move across our forecast area with a rather strong cold frontal passage, which if model timing is correct will produce decent orographic snows for our Laramie, Snowy and Sierra Madre Ranges, and some likely accumulating snow for lower elevations due to the thickness packing along the front, dynamics and synoptic forcing, especially if the track of the system is a bit further south across Colorado, rather than over Wyoming as currently depicted, so please stay tuned to the latest forecasts from your entire National Weather Service team. In any event. Friday the 20th, will be a cold and blustery day with measurable snow becoming increasingly likely at many locations, although snowfall amounts are quite unpredictable for day 7, one week out. Maximum temperatures will only be in the upper 30s to upper 40s with breezy to windy conditions, only six days before Thanksgiving.

AVIATION /12Z TAFS THROUGH 12Z SUNDAY/

Issued at 450 AM MST Sat Nov 14 2026

A Pacific storm system will remain south of the region today, with most of the precipitation south of the Interstate 80 corridor. However, low level upslope flow will continue through tonight across the northern fringe of this system , resulting in persistent low clouds and areas of fog at times.

HAZARDS/WEATHER TRENDS: Persistent IFR to LIFR conditions expected over the eastern plains, including KCYS and all the western Nebraska terminals except KCDR for low clouds and areas of fog...sometimes dense. CIGS may lift to MVFR briefly between 19z and 00z Sunday, but are expected to fall back to IFR in the evening hours (00z to 03z Sunday). VFR conditions will continue for KLAR and KRWL over the next 24 hours with a few light sprinkles or flurries possible.

CYS WATCHES/WARNINGS/ADVISORIES

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