textproduct: Cheyenne

KEY MESSAGES

- Sunday will be dry as an upper level ridge builds over the area.

- Hot temperatures expected Sunday and Monday, with highs topping out in the mid 80s to mid 90s.

- Conditional thunderstorm chances return Monday through at least Thursday in response to increasing moisture.

SHORT TERM /THROUGH MONDAY NIGHT/

Issued at 200 AM MDT Sun Jul 5 2026

All models show a quiet Sunday with dry conditions as a strong upper level ridge axis develops over the Front Range and builds northward. Increasing 700mb temperatures expected with forecast values between 14c to 19c across the region, warmest over central Wyoming. Expect even Rawlins and Laramie to see highs in the mid to possibly upper 80s this afternoon. With dry air aloft mixing down to the surface, resulting from increasing midlevel subsidence associated with the upper level ridge, expect daytime convection to struggle to develop today. High resolution model data all show no shower or thunderstorm activity, so lowered POP below 10 percent through the evening hours. Other than some fair weather CU developing and moving east, mostly sunny skies are expected with relatively light winds becoming south to southeasterly through the afternoon hours. Expect a low level jet around 800mb to develop across the high plains late this evening, which is pretty typical this time of the year in the late evening hours, with winds increasing out of the southeast after sunset. May see some gusts of 30 to 40 MPH in and around the Pine Ridge and the Cheyenne Ridge.

Low level jet will diminish shortly before sunrise on Monday as the upper level ridge axis slowly drifts eastward through the morning hours. The low level jet will result in some moisture advection from the Great Plains with dewpoints returning to the 40s and 50s along and east of the I-25 corridor. With the ridge axis not as strong as Sunday, this will allow a weak shortwave to clip the northern zones Monday afternoon. Expect isolated showers and thunderstorms to develop along and ahead of this shortwave as it digs slightly southeast. Kept POP around 15 to 30 percent Monday afternoon and evening along and east of the Laramie Range. Laramie Valley may get some of this activity, but surface moisture won't be as favorable in the afternoon. Thunderstorms look sub-severe at this time with only about 20 to 25 knots of shear and MLCAPE between 400 to 1000 j/kg, highest over the southern Nebraska Panhandle. Gusty outflow winds appear to be the main threat from any thunderstorm activity. Otherwise, High temperatures will be similar to Sunday and maybe even a few degrees warmer with Cheyenne around 90 degrees for an afternoon high. low level jet will intensify again Monday night, but not quite as strong as Sunday night/early Monday.

LONG TERM /TUESDAY THROUGH SATURDAY/

Issued at 1212 PM MDT Sat Jul 4 2026

The long-term looks to be dominated by a stubborn upper level ridge that will position itself over the four corners area. We will be on the northern end of this ridge which may allow a few subtle shortwaves to pass nearby to add some unsettled weather chances. Otherwise, expect typical early summer time conditions to become more prevalent through at least the next week.

Tuesday through Thursday will keep the conditional afternoon thunderstorm trend going. The plume of monsoon moisture will keep PWATs elevated of 0.75 to 1.5" across the region. Enough low level convergence will provide lift for thunderstorms. Additionally, bulk wind shear of 35-45 knots may be enough to support more organized convection and some severe risks. Machine learning models are highlighting low end chances of severe weather through this period from the GFS ensemble models.

Thursday through Saturday we will focus attention at elevated fire weather concerns. The moisture that had kept relative humidity values up may have advected east and out of the area by this time. Minimum humidity values may drop into the teens and single digits for the western counties Thursday and spread to be area wide Friday and Saturday. High temperatures start rising as well. Some spots may get close to reaching the triple digits for the first time this year during this period. Winds should not be very strong in this ridging regime which will help keep more widespread critical fire conditions down. Fuels are starting to become critical in our western zones. The rains we have gotten the last few weeks have induced flooding in very localized spots and at least an inch in many places, however it was not enough to offset the lackluster winter season we saw. As we go into the hotter and drier portions of summer we anticipate fuels to continue to cure and become more susceptible to combustion and fire spread. Since this is fairly far into the forecast expect changes to details.

AVIATION /12Z TAFS THROUGH 12Z MONDAY/

Issued at 540 AM MDT Sun Jul 5 2026

Upper level ridge axis will build north and strengthen over the area today. Mostly sunny skies and minimal Aviation impacts are expected.

HAZARDS/WEATHER TRENDS: VFR conditions will prevail over the next 24 hours. Southeast to easterly winds will become gusty after 22z today, but mainly between 02z and 10z tonight over the eastern plains terminals and KLAR. Can't rule out some gusts up to 35 knots near KCDR and KAIA.

CYS WATCHES/WARNINGS/ADVISORIES

WY...None. NE...None.