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 MONDAY NIGHT/

Issued at 115 PM MDT Sat Oct 3 2026

The weekend continues to look pleasant as we see temperatures around 10-15 degrees above normal with highs in the 70's to low 80's and subsidence keeping skies mostly clear. Low temperatures overnight into Sunday will be in the widespread 40's, with 40's to 50's as we move into the start of the work week. Dry conditions will also bring elevated fire weather concerns, but widespread critical conditions are not expected.

This changes on Monday as the ridge shifts slightly eastwards directly over us before beginning to flatten a bit later in the day due to troughing to the north. Because of this, 850mb temperatures will surge to just in excess of 31C, and our corresponding surface temperatures will jump into the upper 70's through upper 80's with even a rogue 90 possible, meaning highs 20+ degrees above normal are expected. This will also threaten daily record highs across the entirety of the region, with many cities expected to tie or break these temperatures. Dry air accompanies this as well with RH values plummeting into the mid to low teens for the day, and with winds just breezy enough in the 20-30 mph range, critical fire weather conditions will be possible. A Fire Weather Watch is in effect because of this, with the expectation it will be upgraded. Confidence is high in this forecast with near unanimous agreement in ensembles and probabilistic forecasts; in fact, the spread between the 10th through 90th percentiles for Monday's high in Cheyenne is 1 degree of difference (83-84 F). These conditions should relax a bit moving into the long term, but expect Monday to be likely the warmest day of the month.

LONG TERM /TUESDAY THROUGH SATURDAY/

Issued at 115 PM MDT Sat Oct 3 2026

On Tuesday a diffused upper level trough makes its way into the Four Corners region. This feature would flatten the upper level ridge that has been parked over the area the last few days. The trough would also bring an uptick in moisture, perhaps enough to kick off a few showers and storms over higher elevations. Even with the weakened ridge, our flow is still primarily out of the northwest and the surface will remain dry and warm. Afternoon high temperatures are likely to be in the low to mid 80s north and east of I-25. Mid to high 70s possible west. Relative humidity values in the teens could promote elevated fire weather conditions. Thankfully winds are not expected to be particular strong and overnight recoveries are fair.

Wednesday through Saturday is a rather uneventful stretch from a meteorological perspective. Afternoon highs stay above average in the high 70s to mid 80s. Mostly clear skies are expected. There are no clear signals in model guidance for an appreciable disturbance, just weak zonal flow on the north end of a weak upper level ridge. We may have to wait until next weekend for a chance of a disturbance in this stagnant pattern.

AVIATION /06Z TAFS THROUGH 06Z MONDAY/

Issued at 1122 PM MDT Sat Oct 3 2026

VFR conditions will continue across all terminals for the duration of this TAF period. Overnight, winds generally variable and less than 10 knots. Heading into Sunday, with the diurnal cycle, winds ramp back up between 16Z and 19Z out of the south with gusts as high as 20 to 25 knots.

CYS WATCHES/WARNINGS/ADVISORIES

WY...Fire Weather Watch Monday afternoon for WYZ418>422-427-430-432. NE...None.