textproduct: Cheyenne

KEY MESSAGES

- Dry conditions and above average temperatures will continue through Friday.

- Elevated to critical fire weather conditions possible Friday afternoon into the early evening.

- A pattern change Sunday into Monday will drop temperatures back to near seasonal normals, and bring renewed chances for rainfall primarily in Carbon and Converse counties.

SHORT TERM /THROUGH FRIDAY NIGHT/

Issued at 200 AM MDT Thu Oct 8 2026

Few changes made to the previous forecast package as the stubborn upper level ridge axis will remain over the area at least through Friday. By late Friday, all models show the ridge beginning to break down from west to east as a series of potent upper level troughs move into the Pacific NW late Friday through the weekend.

Remaining pretty quiet today with warmer than average temperatures continuing this afternoon. A few more record high temperatures are possible, with Laramie and Rawlins have the best chance to see daily records broken Thursday afternoon with highs in the mid to upper 70s. Further east, still remaining warmer than average but highs should be several degrees lower than the daily maxes. Can't rule out low 80s for Cheyenne, which will be within a degree or two of the record high of 83 set in 2020. Kept POP below 5 percent since any weak rain shower or thunder shower(s) have stayed south of the Colorado/Wyoming border with weak upslope flow and instability near the Rocky Mountains. Do not expect that to change today.

For Friday, models are now showing a subtle disturbance aloft ejecting northeast into southern Wyoming in the afternoon. This disturbance is pretty weak and barely noticeable with a series of weak vort maxes lift northeast during the evening hours on Friday. High res guidance is starting to pick up on this, but still show only isolated showers and perhaps a rumble of thunder across Carbon and Albany counties...possibly extending eastward into the I-25 corridor. Increased POP Friday evening, but kept most places below 15% since we want to see a little more model consistency. Also, low level moisture will struggle to recover Friday which may greatly limit convection outside of the mountains.

Friday will likely be the warmest day we'll see in a while as the Pacific cold front is expected to impact the area, in some form, this weekend and early next week resulting in a gradual long term cooling trend. Highs will climb back into the mid to upper 80s (perhaps around 90) for western Nebraska as 700mb temperatures increase above 10c to 12c. In addition, west to southwest winds will increase late in the morning and afternoon hours with good subsidence and additional warming off the mountains across far eastern Wyoming. Even in Cheyenne, Wheatland, and Douglas...may see high temperatures in the low to mid 80s. Widespread record highs are possible Friday afternoon with daily maxes dating back to the 1910's to 1950's.

LONG TERM /SATURDAY THROUGH WEDNESDAY/

Issued at 225 PM MDT Wed Oct 7 2026

A pattern change is expected in the long term, with a switch to cooler temperatures and more wet conditions. The change will be gradual over the weekend, with mild temperatures and mostly dry conditions expected for the most part. The forecast area will still be under the influence of southwest flow on Saturday ahead of a trough that will drop into the Pacific Northwest from Canada. As a result, 700 mb temperatures will remain on the warm side, ranging from +10C to +12C. This will cause highs to remain 10 to 20 degrees above average for this time of year. Southwest flow combined with weak vort maxes from the incoming trough could lead to the development of light showers during the afternoon and evening hours. Mid-level moisture will gradually increase over the western portion of the CWA, so Carbon and Albany Counties will have the greatest chance at seeing the shower activity if it manifests. Most guidance does show the best precipitation west and south of the forecast area, so any showers that do develop will likely have little precipitation and not be impactful. A cool down is expected Sunday as the closed low associated with the trough dives south into southern California. This will lower 700 mb temperatures a few degrees, leading to cooler high temperatures. Highs will be knocked down into the 60s and 70s with ample cloud cover helping cool things down. Highs will still be about 5 degrees above average, but will feel much more seasonable. Precipitation chances will be comparable to Saturday, with light showers possible for the western portion of the CWA during the afternoon hours. Precipitation chances will increase overnight as a weak shortwave passes across the area.

The closed low over southern California will stagnate for a few days, allowing upper-level ridging to actually build back into the area. The ridge will keep temperatures fairly stable on both Monday and Tuesday, hovering around average for mid-October. More importantly, the ridge will keep conditions relatively dry. Models show little chance of precipitation on Monday and Tuesday. Precipitation chances return Tuesday night into Wednesday as the upper-level pattern becomes quite messy. The low over southern California will weaken and eventually eject eastward along the Colorado/New Mexico border. Simultaneously, this will interact with the remnants of what is now Tropical Storm Simon. On top of this, yet another trough dropping in from Canada will push into western Wyoming. As a result, Wednesday has the potential to be very wet. Temperatures will stay seasonable, so snow for the lower elevations does not look likely with this system at this time. However, the mountains could see some snow.

AVIATION /12Z TAFS THROUGH 12Z FRIDAY/

Issued at 519 AM MDT Thu Oct 8 2026

VFR conditions will prevail for the TAF period. Mostly sunny skies with typical diurnal winds are expected throughout the day. Little to no aviation impacts are anticipated.

CYS WATCHES/WARNINGS/ADVISORIES

WY...Fire Weather Watch from Friday afternoon through Friday evening for WYZ417>422-425-427-432. NE...Fire Weather Watch from Friday afternoon through Friday evening for NEZ434.