textproduct: Cheyenne

KEY MESSAGES

- Strong ridging aloft will produce a dry and hot period for today through Tuesday, with the primary challenges being the above normal heat and fire weather conditions.

- Isolated high-based thunderstorms possible on Thursday through Saturday mainly near the mountains. Arrival of the monsoon possible later in next weekend.

SHORT TERM /THROUGH MONDAY NIGHT/

Issued at 121 PM MDT Sun Jul 12 2026

An upper-level ridge will dominant through the short term, keeping skies mainly clear for most of the forecast period. This will bring good news and bad news. Lets start with the good news, expect primarily beautiful sunny afternoons, with ample heating as highs will soar into the 90s to near 100. The bad news, this heat coupled with min RH values tanking to as low as 5% across southeast Wyoming and to 15% for portions of the Nebraska Panhandle, makes the environment prime for elevated to critical fire weather conditions/concerns as fuels continue to dry out. Therefore, we have Red Flag Warnings out through Monday afternoon. Our hi-res guidance suite doesn't show much in the way of any possible relief due to shower and/or thunderstorm activity as the output shows virtually nothing. Rinse and repeat for Monday, with the upper-level ridge continuing to dominate, dry conditions will continue and so will the Red Flag Warnings. The aforementioned Red Flag Warnings are not only out due to the dry/hot conditions, but the winds will ramp up ever so slightly with gusts to around 25 mph due to a strengthening mid- level jet, primarily along and east of the I-25 corridor. With enough subsidence, some of the stronger winds will mix down to the surface, causing those higher gusts. The 'warm' days will continue as lows only dip into the 60s/70s and as such, the Heat Advisory we are under will extend into the long term period as highs continue to soar into and through the 90s, with many locations possibly hitting the century mark.

LONG TERM /TUESDAY THROUGH SUNDAY/

Issued at 121 PM MDT Sun Jul 12 2026

The weather over the medium to long range will be dominated by the quasi-stationary upper level high. This upper level high forecast to remain over the south-central to central United States, including the Rocky Mountain region. Therefore, not expecting conditions to change too much through next week with hot temperatures. However, record high actually appear unlikely at this time since we are heading into the warmest week of the year, climatologically speaking. For early in the week, center of the 600dm upper level high will be generally located in the central Rocky Mountain region extending east into the central Great Plains. Forecast high temperatures will remain in the 90s for most of southeast Wyoming, including the high valleys west of the Laramie Range. For western Nebraska, 95 to 105 expected each day. South to southeasterly winds should continue each day with increasing confidence in a decent breezy for the late morning hours and the afternoon. This should result in slightly cooler temperatures across the south facing ridges and hills due to localized upslope, but we're talking about a difference between 91 an 96 degrees, so the overall cooling will be minimal.

As we head into later in the week and the weekend, models are now showing different solutions in regards to the position of the upper level high. The 12z ECMWF maintains the upper level high over Wyoming, Utah, and northern Colorado...similar to yesterday while the GFS and Canadian now show the center of the high drifting southeast into the south central plains. The key difference between both solutions in not necessarily the temperatures, which is still expected to be very warm to hot across the forecast area, but precipitation chances. GFS and Canadian show the Monsoon plume over Colorado and Wyoming by the weekend with increasing thunderstorm chances. Will keep an eye on this trend over the next few days, with a mention thunderstorms along and west of the Interstate 25 corridor for now.

AVIATION /06Z TAFS THROUGH 06Z TUESDAY/

Issued at 1132 PM MDT Sun Jul 12 2026

Breezy conditions are expected at most of the Nebraska panhandle terminals this evening and tonight as a low-level jet develops. Wind gusts up to 25 kts will be possible. Southeast Wyoming terminals can expect lighter winds. Similar conditions are expected tomorrow with mostly sunny skies and diurnal afternoon wind gusts.

CYS WATCHES/WARNINGS/ADVISORIES

WY...Heat Advisory until midnight MDT Wednesday night for WYZ101- 102-107-108-118-119. Red Flag Warning until 8 PM MDT Wednesday for WYZ417>420-423- 427-430>433. NE...Heat Advisory until midnight MDT Wednesday night for NEZ002- 003-019>021-054-055-095-096. Red Flag Warning until 8 PM MDT Wednesday for NEZ434>437.