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 Wednesday through the end of the week, along with a slow cooling trend. Temperatures will remain above normal though.

SHORT TERM /THROUGH MONDAY NIGHT/

Issued at 233 AM MDT Sun Jul 12 2026

Welcome readers to another day where we get to play are we going to reach convective temperature or not! The upper level ridge will remain parked over the Intermountain West today keeping the skies relatively clear for the better part of the day. The high temperatures will once again be in the 90's to 100's today. RH values will float between 5 to 15 percent in Southeast Wyoming and between 15 and 25 for the Nebraska Panhandle. This means when you're outside it will be a dry heat and wont realize you are sweating especially if you're in Carbon County where the lowest RH values are forecasted. Your body will constantly cool yourself through evaporative cooling leading you to dehydrate faster. Because of these high summer temperatures the heat advisory will remain in place especially since Laramie, Wy was pretty much the only place to drop below 70 degrees before midnight-1am. A weak shortwave will be moving through the region today giving us some gusty winds that may help you feel like you're cooling off or possibly feeling like your in an air dryer in these hot conditions. The Low RH values and breezy winds today are the reason a Red Flag goes into effect this afternoon and also a reason to just put down the matches and lighters because if the fuels aren't already critical (80 percent of our forecast area) they probably will be in a couple days. The Red flag expires Monday evening as these dry conditions are expected to persist through Wednesday, it will probably be reissued come Monday night. Now where the convective temperature comes in, if the shortwave comes through during the time where we hit the convective temperature we will get a few clouds and probably some brief showers. However with the soundings having the temperature and dewpoint so far apart you can land a C-130 on it, the precip will probably not reach the ground and you will just get virga and gustier winds underneath them. So today, do EMS a favor and hydrate and eat some light snacks so you keep nutrients and vitamins in your body to prevent waterlogging your body and heat related injuries.

LONG TERM /TUESDAY THROUGH SATURDAY/

Issued at 123 PM MDT Sat Jul 11 2026

The weather over the medium to long range will be dominated by the quasi-stationary upper level high, forecast to remain over the south-central to central United States, including the Rocky Mountain region. To put it in perspective, models show the position of the upper level high (center) drifting westward by a few hundred miles from Monday to next Saturday. Therefore, not expecting conditions to change too much through next week.

For early in the week, broad center of the 600dm upper level high will be generally located in the central Rocky Mountain region extending northeast into the Great Lakes region. GFS and ECMWF standardized 500mb anomalies show between 1-3 SD's above average...which is pretty impressive since we're currently entering the hottest week of the year...climatologically speaking. Forecast high temperatures will be 90s for most of southeast Wyoming, including the high valleys west of the Laramie Range. For western Nebraska, 95 to 105 expected each day. There may be some silvering lining for the south facing ridges. Due to south to southeasterly winds, some localized upslope may prevent temperatures from climbing even higher. Kept temperatures a few degrees cooler (compared to the surrounding areas) in these locations, which include Cheyenne, Kimball, Sidney, Alliance, and Lusk. However, any westerly wind shift or light and variable winds will result in a rapid warm-up.

As we head into later in the week, center of the upper level high will drift overhead, and even retrograde westward a bit. Although winds will remain out of the southeast, or shift into the east during this time, wind speeds will decrease or become light and variable. This may actually lead to the hottest temperatures over the south facing ridges. Otherwise, temperatures will be a few degrees cooler across most of the area...although it will be hardly noticeable. Ensembles and NBM 75th to 90th percentile show high temperatures only a few degrees higher than the current forecast, so kept high temperatures close to the 50th percentile of the NBM. Low confidence on any precipitation during this time. Subtropical monsoon moisture is expected to creep north out of Mexico and the southwestern US. However, the position of the upper level high overhead may result in the monsoon moisture plume over Idaho, Utah, and western Wyoming. Therefore, most of the mention of POP and thunderstorms will be limited to the mountains and adjacent valleys for now through next Saturday.

AVIATION /06Z TAFS THROUGH 06Z MONDAY/

Issued at 1040 PM MDT Sat Jul 11 2026

VFR conditions are expected to continue through the TAF period as high pressure sits over the area. Mostly clear skies are forecast through the night with relatively light winds. Winds will increase during the day tomorrow, with diurnal wind gusts of 20 to 30 kts.

CYS WATCHES/WARNINGS/ADVISORIES

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