textproduct: Cheyenne

KEY MESSAGES

- A High Wind Warning has been issued for much of Carbon County and portions of Albany County from 5AM to 3PM today.

- Above average temperatures will continue today, but a weekend system will drop temperatures near to below average.

- Precipitation is possible this afternoon through Sunday, with the potential for frozen precipitation outside of the mountains Sunday morning.

- Near normal temperatures and a bit warmer by Tuesday into Wednesday, but next Pacific system will be approaching from the Pacific Northwest by the middle of the week.

SHORT TERM /THROUGH SATURDAY/

Issued at 326 AM MDT Fri Oct 23 2026

The upper-level trough that has been moving towards the region over the past few days will start to significantly impact western portions of the CWA starting this morning. The upper-level trough is currently located over Nevada and Oregon, with a modest jet developing as the ridge starts to move off towards the Mississippi River Valley. The upper-level system will strengthen this afternoon and evening as split flow develops over the Intermountain West. A much stronger 250mb jet is anticipated to develop overhead this afternoon and evening. A few lobes of 500mb vorticity eject out ahead of the incoming trough this afternoon, adding to the synoptic forcing across the region. Much of the area will be under the right entrance region of the upper-level jet into the overnight hours, favoring increased forcing. The 700mb trough currently looks to remain on track, with a northeasterly jump from northern Nevada into southern Montana this morning. The trough will deepen slightly this morning, resulting in strong height gradients across much of the area and a 50kt, southwesterly jet across western portions of the CWA. GFS Omega fields suggest modest downward motion across western Carbon County with the increasing 700mb jet overhead, favoring downward acceleration. The surface pressure gradient looks to increase this morning and afternoon for this same area as the surface low over eastern Montana deepens throughout the day. While the strong 700mb jet will quickly weaken into the afternoon hours as the 700mb trough continues to move quickly to the northeast, this will not occur before very strong winds develop across western Carbon County. In-house Random Forest guidance suggests around a 20% chance for high winds at Rawlins so, with recent model runs starting to increase the 700mb jet this morning, a High Wind Warning has been issued for much of Carbon County and portions of Albany County, including the Arlington/Elk Mountain wind prone zone. Sustained winds between 30 and 35mph are expected for much of the mid-morning hours with gusts likely between 55 and 60mph, though a rouge gust up to 65mph cannot be completely ruled out at some of the wind prone locations.

As far as precipitation is concerned for Friday into Saturday morning, southwesterly surface flow across Carbon County will not only produce strong winds, but will also favor upslope development across the Sierra Madre Range, with precipitation starting to push northeastward Friday evening into the overnight hours. 700mb temperatures will start to decrease this afternoon into the 2 to 4C range across Carbon County, while remaining quite warm east of this, in the 6 to 8C range. As a result, precipitation across the Sierra Madre Range looks to start as mostly rain, with warmer 700mb temperatures not supporting snow development. However, into the overnight hours and early Saturday morning, 700mb temperatures drop to at or below 0C across the mountains. This would favor rain switching to snow Saturday morning, though significant accumulation is not anticipated. Any precipitation outside of the mountains should remain primarily rain, as recent model runs suggest a slightly warmer system than originally thought.

LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/

Issued at 326 AM MDT Fri Oct 23 2026

No major changes, please see previous discussion...

Into the long term our temperatures will drop several degrees below average under a colder airmass with some increasing chances for precipitation, primarily for our eastern zones this time, with temperatures then warming to near average by the middle of the work week under brief clearing. The upper level pattern will see the northern trough quickly accelerating eastwards, leaving us under southwesterly flow aloft from a brief finger of weak transient ridging that will quickly be erased by low pressure slowly progressing across the Four Corners region. This will then become our main weather feature through Monday before finally sliding eastwards into the Central Plains, with another transient ridge building on Tuesday that will briefly hold the region before another Pacific low moves into the Pacific Northwest and then starts to knock on our doorstep by Wednesday into Thursday. Under this pattern, we should see surface flow begin to weaken by later Saturday and continue into the early part of next week as the strongest part of the jet remains just south and west of the forecast area. With this flow, the best moisture will remain just outside of our forecast area to the east as well. That being said, PWAT values will still be on the higher side even for our area by around 0.15-0.25 inch, and scattered shower activity is expected from Saturday afternoon and continuing through Monday evening before exiting the region. The highest QPF amounts should align with the best moisture for the southeastern portions of the Nebraska Panhandle, but some meager moisture should occur across most of the forecast area east of the Laramie Range. Morning lows both Sunday and Monday could also allow for this to mix with snow, but don't expect noteworthy winter accumulations at this time. As conditions finally clear later Monday into Tuesday and the transient ridge moves in, 700mb temperatures will warm back into the 5-8 C range, allowing surface temperatures to rise back to near average in the 50- 60 degree range. Tightening pressure gradients from the approaching Pacific system will start to increase westerly to southwesterly winds again for our western zones on Tuesday and Wednesday, but otherwise expect conditions to be a bit more uneventful as precipitation chances dwindle outside of the high terrain for the middle of the week.

AVIATION /06Z TAFS THROUGH 06Z SATURDAY/

Issued at 1139 PM MDT Thu Oct 22 2026

Clouds continue to move across the area, but will likely not cause any issues as CIGs will remain VFR. Cannot rule out a light shower early in the morning, mainly west of the Laramie Range. If showers do develop, visibility impacts are not anticipated. Winds are light, but will increase as winds aloft strengthen. Gusty winds are expected by mid to late Friday morning.

CYS WATCHES/WARNINGS/ADVISORIES

WY...High Wind Warning until 3 PM MDT this afternoon for WYZ104-105- 109>111. NE...None.