textproduct: Cheyenne

KEY MESSAGES

- Windy conditions return Sunday afternoon for the known wind prone locations through most of Monday.

- Above normal, near record temperatures and benign conditions through most of the week.

- Strong gusts alongside more record warmth expected on Christmas Day, followed by temperatures cooling slightly next weekend.

SHORT TERM /THROUGH MONDAY/

Issued at 212 AM MST Sun Dec 21 2025

Two features will bring us a quick round of gusty winds again on Sunday, that being a ridge deepening over a majority of the US and a shortwave trough riding the periphery of this high across the northern US and southern Canada. With the ridging strengthening, expect temperatures to rocket back up to record levels, with highs Sunday generally warm but below records, but by Monday we'll be seeing widespread highs in the 60's east of I-25, with locations to the west generally in the 50's outside of the mountains. Meanwhile the tightened pressure gradient from this system will enhance the low level jet, and alongside favorable descent from negative omega values, 700mb winds around 65-75 knots should make their way down to the surface. Most likely locations for strong winds will be our normal wind prone locations of Bordeaux, Rawlins, and the Laramie Summit/Foothills, but have also added in the Rawlins area to the warning as conditions look favorable for some stronger southwesterly gusts here as well. Winds should develop beginning later into the afternoon today and will persist through Monday morning, lessening by the afternoon. Finally this system may bring a few very isolated showers or some light snow showers to the mountains, but QPF will be minimal overall with significant impacts unlikely.

LONG TERM /MONDAY NIGHT THROUGH SATURDAY/

Issued at 212 AM MST Sun Dec 21 2025

Long term also remains dominated by the large ridge above, with dry conditions and near to record warmth through Christmas day before another system moves in to briefly disrupt the pattern and cause another round of high winds and mountain precipitation to end the week and move into a (slightly) cooler weekend.

With the high dominating, look for conditions to remain benign Tuesday and Wednesday for the most part outside of significantly warm temperatures at near to record levels. Highs will remain in the 60's east of the I-25 corridor and in the 50's outside of the mountains to the west. Wednesday night into Thursday, the approaching shortwave will begin to make its influence known, causing some precipitation to creep into the mountains and also increasing winds with breezy westerlies to southwesterlies expected. That being said, the strongest conditions with near high wind warning levels aren't expected to occur until Christmas morning or so, and models have backed off on the expected strength for now with in house guidance not as excited for this event as it was previously. Still, knowing the region, we'll likely see at least a few gusts to high wind warning levels, and as usual likely for our wind prone zones.

Meanwhile throughout this event we should see a steady stream of weak moisture that should produce a bit of precipitation for the mountains and perhaps the zones just adjacent, but the majority of this activity will be fueled by upslope flow and therefore be relegated to the mountains themselves. This should produce steady, light snowfall, and from Christmas morning through Saturday we should see advisory amounts of around 6-12 inches with localized heavier totals primarily for the Sierra-Madre range as the southwesterly flow component may shadow the Snowy Range.

Moving into the end of the week and the weekend, the ridge will flatten and become a bit more broad, and while we won't see more seasonable temperatures return quite yet, highs should drop back into the 40's to 50's across the region with benign weather once again returning to end the long term. Once again ensemble clusters look very similar to each other with minimal discrepancies, leading to a high confidence (80-90%) in the forecast. Whoever asked for warm temperatures for Christmas is definitely getting their wish!

AVIATION /12Z TAFS THROUGH 12Z MONDAY/

Issued at 423 AM MST Sun Dec 21 2025

VFR conditions over the next 24 hours. CIGs mid to mostly high levels, possibly SKC at times. Winds will be the main story, becoming breezy from the south to southwest this morning into the afternoon with strongest gusts at WY terminals. Low level wind shear will also accompany with most sites seeing some form of shear starting during the afternoon or early evening.

CYS WATCHES/WARNINGS/ADVISORIES

WY...High Wind Warning from 2 PM this afternoon to 2 PM MST Monday for WYZ106-109-110-116-117. NE...None.