textproduct: Cheyenne

KEY MESSAGES

- Strong ridging aloft will produce a dry and hot period for Sunday through Tuesday, with the primary challenges being the above normal heat and fire weather conditions. Isolated high based thunderstorms will be possible on Wednesday over and near the mountains, with coverage slowly increasing Thursday and Friday, along with an attendant slow cooling of daytime maximum temperatures.

SHORT TERM /THROUGH SUNDAY NIGHT/

Issued at 222 AM MDT Sat Jul 11 2026

The upper level ridge becomes a little more stout as it builds over us. The subsident flow from the upper level ridge will start to mix in dry air from the upper levels of the atmosphere and bring it down to the surface. This will also reduce the number of clouds in the sky raising the surface heating efficiency in our region. Even in southerly flow this may help over perform what the models think the high temperature for the day is supposed to be. So today will be fairly sunny with temperatures in the 90's with some of our northern counties possibly reaching 100 today. Humidity levels will also drop in the afternoon to around 15 percent or lower in Southeast Wyoming and around 20-25 percent for the Nebraska Panhandle. With the winds expected to be light and no showers forecasted, the environment is in an elevated fire state for today. However, it is interesting to note that the NAM NEST, FV3, and the ARW want to populate some light showers between 18z and 21z today. The NAM Nest has some sort of stationary boundary that isn't seen in the surface observations with easterly winds forming an upslope convergence boundary to produce some showers along Platte and Goshen County. The NBM had random 12 pops around that time with QPF outputs near a tenth forming little bullseyes across Goshen and Sioux county. Those were taken out as the surface will be too dry and there really wont be much to lift but we shall see if I'm wrong or not today. For Sunday, the fire watch was upgraded to a red flag warning that now lasts through Monday evening. A system will be moving across Canada compressing against our ridge to give the intermountain west a boost in gradient winds that looks to be strong enough for the Red Flag criteria with gusts above 25 mph. The Heat advisory was extended as well until 06z Wednesday or midnight Tuesday as the ridge remains in place over us for that long to give our region temperatures near or exceeds 100 degrees during the day and we dont really drop below 70 at night until 3-4am looking at the models. So this weekend is the perfect time to go out and enjoy the local festivities, however just remember to stay hydrated and have a couple snacks to prevent heat injuries while doing them.

LONG TERM /MONDAY THROUGH FRIDAY/

Issued at 1230 PM MDT Fri Jul 10 2026

Sunday through Thursday...Primary challenges will be the heat and fire weather conditions. A 5980 dekameter 500 mb ridge lies over Wyoming Sunday morning, moving to the northern Great Planes Monday morning, and then remains entrenched across the northern Rockies and northern Great Planes through the period. Models suggesting typical monsoonal moisture creeping into our counties Wednesday through Friday with weak perturbations and some mid level moisture to spark isolated to widely scattered thunderstorms over and near the Snowy and Sierra Madre Ranges, as well as the Southern Laramie Range and Laramie Valley from Wednesday through Friday, with coverage of storms slowly increasing through that aforementioned period.

Ridging aloft dominates our region, with quite dry air at low and mid levels, accompanied by typically toasty 700 mb temperatures, thus chances for late day showers and thunderstorms will be nearly nil and non existent, and dry weather will prevail through Tuesday.

The 700 mb temperatures will yield maximum temperatures mainly in the 90 to 105 degree range. Weak perturbations and a slight increase in mid level monsoonal moisture may spark isolated high based thunderstorms on Wednesday, and moreso on Thursday and Friday, again dependent on how much mid level monsoonal moisture advects into our CWA, County Warning Area.

AVIATION /18Z TAFS THROUGH 18Z SUNDAY/

Issued at 1122 AM MDT Sat Jul 11 2026

VFR conditions will prevail across all terminals for the duration of this TAF period. Winds will gust up to around 20 knots for most of the daylight hours today, winding down during the evening. As the surface gradient tightens Sunday, expect winds to ramp up again across all sites with southerly gusts topping out around 25 knots by about 18Z Sunday.

CYS WATCHES/WARNINGS/ADVISORIES

WY...Fire Weather Watch through Sunday morning for WYZ417-418-423- 430>433. Heat Advisory until midnight MDT Tuesday night for WYZ101-102- 107-108-118-119. Red Flag Warning from noon Sunday to 8 PM MDT Monday for WYZ417>420-423-427-430>433. NE...Fire Weather Watch through Sunday morning for NEZ434. Heat Advisory until midnight MDT Tuesday night for NEZ002-003- 019>021-054-055-095-096. Red Flag Warning from noon Sunday to 8 PM MDT Monday for NEZ434.