textproduct: Cheyenne

KEY MESSAGES

- A heat wave will build into the area Saturday through Monday, producing near record high temperatures for Sunday.

- Elevated to near critical fire weather conditions are expected Sunday and Monday.

- Some relief of the heat is possible during the middle of next week as a Canadian cold front moves towards the Front Range.

SHORT TERM /THROUGH SUNDAY NIGHT/

Issued at 1221 AM MDT Sat Aug 1 2026

The main weather headline for the short term period will be a dominate ridge building across the region, bringing benign weather along with soaring temperatures, especially for Sunday. So for today, expect highs to top out around 90 along the I-80 corridor and mid to upper 90s from the Platte River and north. We should remain below daily record highs, but more hot days are coming. In addition, for Saturday night we anticipate pressure falls over western Wyoming which in turn will increase the pressure gradient over the High Plains, leading to increasing southerly winds with gusts topping out in the 30-40 mph range. This will lead to very warm overnight lows as temperatures only dip into the low to mid 60s through Sunday morning. Heading into Sunday, the proper ingredients will be in place to see temperatures soar and flirt with records highs, possibly all-time record highs such in Chadron with downsloping winds off of Pine Ridge. Most of the temperatures across the area are at or near the 99th percentile and/or all time maximum high temperatures. We are expecting the hottest temperatures to occur in Sioux, Dawes and Box Butte Counties in the Nebraska Panhandle where highs top out in the low to mid 100s. Here in Cheyenne and across eastern Wyoming, highs will climb into the upper 90s to low 100s. With these forecast high temperatures and dry air, a Heat Advisory has been issued for a good portion of the CWA during the afternoon hours on Sunday. The other thing that we are monitoring with the southerly winds across the Nebraska Panhandle are the increased fire weather concerns as min RH values dip to and below 15 percent, so stay tuned...

LONG TERM /MONDAY THROUGH FRIDAY/

Issued at 225 PM MDT Fri Jul 31 2026

On Monday, the ridge flattens somewhat as a shortwave trough aloft and its associated cold front enter our counties from the north, cooling off temperatures rather significantly across our northern counties and there may be enough available moisture for isolated late day thunderstorms over the southern Laramie Range.

Then on Tuesday, expect a relief from the summertime heat in the wake of a passing Canadian origin cold front, sending maximum temperatures back into the mid 70s to mid 80s. Moisture looks scant, perhaps enough for isolated to widely scattered late day thunderstorms near the southern mountains.

For your Wednesday...Brisk west northwest flow aloft continues and with progged 700 mb temperatures near 18C, we anticipate maximum temperatures to rise into the 80s. Models indicate a dry punch at low and mid levels, effectively cutting off any convection chances due to warm temperatures aloft producing plenty of CIN, Convective Inhibition.

Then on Thursday...The heat returns in the warm sector that our counties will be in to the warm side of the cold front, with maximum temperatures well into the 90s at most locations. With scant low and mid level moisture, no showers or thunderstorms are expected.

For your Friday, the end of the traditional workweek...the heat continues with highs in the 90s. Not totally buying the GFS progged Canadian origin cold front sweeping across our counties and providing heat relief, though your National Weather Service forecast team will monitor future model trends to see if the cooler push will come to fruition. Continued dry with limited atmospheric fuel, moisture availability.

AVIATION /18Z TAFS THROUGH 18Z SUNDAY/

Issued at 1118 AM MDT Sat Aug 1 2026

High confidence that VFR conditions will remain in place through the TAF period as Southeastern Wyoming and Western Nebraska are located underneath a ridge of high pressure in a NNW flow pattern aloft. Expect the typical diurnal onset of shallow, high-based cumulus this afternoon until sunset, with mostly clear skies otherwise. For areas east of the Laramie Range, winds will remain out of the S/SE around 10 knots, until gusts peak as high as 25-30 knots, primarily at KCDR and KBFF thanks to the onset of a SSW nocturnal low-level jet. For KLAR and KRWL, variable winds of 5-10 knots will prevail.

CYS WATCHES/WARNINGS/ADVISORIES

WY...Heat Advisory from 11 AM to 9 PM MDT Sunday for WYZ101-102-104- 107>109-111-118-119. NE...Heat Advisory from 11 AM to 9 PM MDT Sunday for NEZ002-003- 019>021-054-055-095-096.