textproduct: Cheyenne

KEY MESSAGES

- Much colder temperatures today with well-below average temperatures expected through early Monday morning with low temperatures in the single digits and below zero.

- Gradual warming trend Monday through Wednesday with periods of very windy conditions across the wind prone areas of southeast Wyoming.

SHORT TERM /THROUGH MONDAY NIGHT/

Issued at 325 PM MST Sun Dec 28 2025

Gusty winds continue across most of the forecast area this afternoon as the CWA sits in strong northwest flow on the backside of the upper-level trough that brought the arctic air. High Wind Warnings continue for Arlington and the South Laramie Range and foothills with gusts of 60 to 65 MPH. Blowing snow has been observed along Interstate 80, mainly along a 20 miles stretch of highway near Arlington. Visibilities have dipped below a half mile at times. Isolated blowing snow has also been seen at Pumpkin Vine near the Colorado border on US-287, reducing visibility. Winds will ease this evening as the trough pushes further east into the Great Lakes Region. Clear skies and calmer winds overnight will cause temperatures to tank from radiational cooling. Since the NBM doesn't usually have temperatures cold enough after an arctic front on clear, calm nights, decided to drop low temperatures well below NBM guidance. Went ahead and lowered temperatures in the high valleys out west below zero due existing snowpack. Wind chills overnight will be below zero, with the coldest wind chills expected in the northern Nebraska panhandle. Thought about issuing a Cold Weather Advisory for this area, but held off as wind chills will be marginal for a Cold Weather Advisory with wind chills just touching -20F for a brief window.

Those heading out early on Monday will find a frigid morning as temperatures are slow to warm. Sunny skies and light winds will help conditions warm up during the afternoon hours. Highs will be warmer than today, with temperatures hovering around average for late December. Precipitation is not expected as upper-level ridging begins to move onto the west coast.

LONG TERM /TUESDAY THROUGH SUNDAY/

Issued at 325 PM MST Sun Dec 28 2025

Weather, what weather, not so much to talk about in the long term as ridging slides in and dominates conditions across the CWA for most of the upcoming work week. So, keep those sunglasses out as that globe in the sky will be ever so bright under mainly clear skies. Also, those shorts and flip-flopps might come in handy with highs soaring into the 40s and 50s, even the low 60s for a few locations across eastern Wyoming and the Nebraska Panhandle. Nighttime lows, as a whole, are expected to only dip into the 20s through extended. All this is due to upper level ridging that slides across the Intermountain West into our region by Wednesday, weakening a bit Thursday as energy moves in from the west. This upper level energy will increase cloudiness and chances of precipitation, with the greatest threat across our western forecast zones late Thursday through Friday morning. The bulk of the precipitation will not make it to or much past the I-25 corridor. Then, ridging makes a triumphant return once again late Friday into Saturday morning, ending any threat of precipitation. Finally, heading into next weekend, the potential for another system to impact our CWA, once again primarily west of the I-25 corridor, increases. In-house guidance have differing solutions of timing and placement of the precipitation, so there is plenty of time between now and then to fine tune the forecast. Winds, which have been hammering our known wind prone areas over the previous several weeks, will continue to be weaker and we get a reprieve from any major events for the duration of the long term period.

AVIATION /00Z TAFS THROUGH 00Z MONDAY/

Issued at 420 PM MST Sun Dec 28 2025

VFR conditions will prevail across all terminals for the entirety of this TAF period. Strong winds that continue to plague several of the terminals, with gusts topping out near 50 knots, will continue through about 03Z this evening and then diminish to less than 10 knots for the remainder of the TAF period. LLWS is possible for KCYS from 05Z to 12Z Monday as the winds diminish this evening into the overnight hours.

CYS WATCHES/WARNINGS/ADVISORIES

WY...High Wind Warning until 8 PM MST this evening for WYZ110-116- 117. NE...None.