Cheyenne forecast discussion

Short Term /Through Friday Night/

Issued at 1232 PM MDT Thu Oct 22 2026

Short term forecast remains seasonably warm with above average temperatures but accompanying this will be chances of precipitation. At the upper levels, a deep low is moving inland across California and will continue to lift northeast through Friday. Unfortunately for our precipitation chances, this system will see it's energy split into two segments - the initial cutoff low will become absorbed into troughing to the north in Central Canada and merge with this feature, while the remnant energy will continue eastwards and form a new cutoff low that will be approaching the Four Corners region by Saturday morning. This means our forecast area will sit in a split flow that will not favor increased moisture, but we could see some gusty winds alongside areas of showers today with Friday a bit drier.

For this afternoon and tonight, a plume of moisture lifting up across the region with PWAT values in the 0.6-1.0 inch range alongside some meager forcing including orographic lift will produce areas of showers across the high terrain of our western zones, primarily Carbon and Albany Counties. Some of this activity may be able to make it off of the high terrain and down into the lower elevations including portions of Platte and Laramie Counties, but should struggle to survive much further east than this thanks to increasing stability despite much higher moisture values. Also of note, very weak instability is expected across this area, which may allow for some thunder but not much more.

Overnight and into tomorrow morning widespread cloud cover will insulate the region and prevent lows from dropping any further than the mid 40's to mid to upper 50's. While this shouldn't bring record warm low temperatures, this will be around 20 degrees above normal for this time of year, allowing for a relatively muggy start to Friday morning. We'll see this moisture clear out however as a dry slot overspreads and mostly removes our precipitation chances for the day. The one exception to this will be late Friday into Saturday morning along and ahead of a cold front that will be moving across the region ahead of the stronger system lifting into Canada. Enough forcing won't be present until this feature is already halfway through our region, but expect a chance at some scattered showers across extreme southeastern Wyoming and through the Nebraska Panhandle. This dry air on Friday will also drop our minimum daytime RH values back into the 20-30% range east of the Laramie Range, and while not critical, this will bring an elevated risk of Fire Weather conditions alongside the other story for the day - strong winds. While the split in flow will somehow avoid the CWA almost fully, with a 700mb jet max both to our east and northwest, elevated winds will be likely during the morning and afternoon for our western and northern zones, with another quick fork of the jet grazing our region around midnight and increasing winds from the I-25 corridor eastwards through the nighttime hours. The strength of this feature won't be enough to promote wind highlights for the region, but should bring some gusty conditions for the time period. The aforementioned cold front will then begin to drop our temperatures, with overnight lows in the 30's to 40's as we move into the weekend where temperatures will become below average.

Long Term /Saturday Through Thursday/

Issued at 1232 PM MDT Thu Oct 22 2026

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 /00Z Tafs Through 00Z Saturday/

Issued at 557 PM MDT Thu Oct 22 2026

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

Cys Watches/Warnings/Advisories

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

SHORT TERM...CG LONG TERM...CG AVIATION...SF