textproduct: Cheyenne

KEY MESSAGES

- Dry conditions and above average temperatures will continue into the next week.

- Fire weather concerns will increase on Monday alongside a chance at record high temperatures.

SHORT TERM /THROUGH TUESDAY NIGHT/

Issued at 1212 AM MDT Mon Oct 5 2026

Heading into the start of the work week, warmer and drier conditions are expected for Monday. Although the ridge over the Four Corners will begin to weaken, 700 mb temperatures will continue to rise. 700 mb temperatures will warm above +12C, which is above the 99th percentile for NAEFS climatology. The anomalously warm air aloft will lead to a hot fall day, with highs ranging from the upper 70s to low 90s. As a result, a few locations are likely to break record highs. Records will most likely be broken in southeast Wyoming, however it is possible that a few Nebraska locations will be within a degree or two of current records. With the ridge weakening, winds will turn more westerly, leading to breezy conditions across southeast Wyoming during the afternoon hours. Westerly winds will cause downsloping and dry conditions, leading to critical fire weather conditions. With no precipitation chances in sight, Red Flag Warnings are already in place for Monday afternoon for portions of southeast Wyoming. Winds will ease Monday night after sunset, however overnight humidity recoveries are expected to be poor.

With the ridge continuing to break down on Tuesday, temperatures will be slightly cooler compared to Monday. The weakening ridge will allow for northwest flow over the area, which will lower high temperatures a few degrees. However, 700 mb temperatures will still remain in the 99th percentile and above per NAEFS climatology, meaning that it is possible a few record highs could be broken or tied once again on Tuesday. There will also be a weak disturbance aloft over the Colorado/Utah border. As a result, some Hi-Res guidance does show the potential for a few light showers sneaking into the high terrain during the afternoon hours. The surface and the mid-level still remain very dry, so precipitation chances will remain under 15 percent for the time being.

LONG TERM /WEDNESDAY THROUGH SUNDAY/

Issued at 220 PM MDT Sun Oct 4 2026

Not a whole lot of interesting developments in the long term from previous forecasts. A weak NW flow regime is in place while an upper level low bats back the ridge to our south. The weaker ridging pattern will allow temperatures to lower a tad Wednesday through the end of the forecast period, which is a plus. Highs in the 80s east and 70s out west. Lows in the 50s and 40s. Humidity values stay low, in the low 20s and teens and winds start increasing ahead of the next Pacific trough. Global models are starting to come into focus on this system. The evolution is still uncertain, particularly on how compact and amplified this trough enters the scene, but the presence of this system is becoming more certain. A compact system would bring greater southwesterly winds. Not the greatest news when combined with the dry afternoon humidities for elevated fire concerns next weekend.

The ensembles start diverging greatly on Sunday. A cold front in some of the solutions is driving a nearly 10 to 25 degree spread in ensemble members. A good cold front and Pacific system would bring in rain and storms. Temperatures would still be on the warm side for snow, outside of mountains.

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/

Issued at 514 AM MDT Mon Oct 5 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...Red Flag Warning from noon today to 6 PM MDT this evening for WYZ418>422-427-430-432. NE...None.