textproduct: Cheyenne

KEY MESSAGES

- Afternoon and evening storms, some of which may become strong to severe, will be possible this afternoon along and east of I-25.

- Sunday will be the driest day 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 SUNDAY NIGHT/

Issued at 1212 PM MDT Sat Jul 4 2026

A lovely Independence Day is in store under mainly sunny skies, light winds, and temperatures soaring into the 80s to low 90s, warmest primarily east of the I-25 corridor. Why the sunny skies and warmer temperatures, well lets take a brief look aloft. Some changes are in store over the next day or so with a ridge building in from the south, this will be the dominant weather feature in the short term period. Therefore, there has been some changes in hi-res guidance from previous runs in the aerial coverage of showers and thunderstorms for this afternoon. Latest runs depict most of the activity initiating just outside of our CWA. This is in part of model initialization of the shortwave aloft a bit further east then what yesterday's runs showed. Now, the upper level shortwave will eject out earlier, meaning an end to the threat of strong to severe storms. So, if a storm develops in the environment we are in, the primary threat will be large hail and gusty winds. Instability parameters have decreased slightly from days prior with CAPE values of up to 1500 J/kg, this combined with bulk shear 0-6km of 30 knots, is still capable to produce strong to severe storms. The bulk of the activity should end by 7pm this afternoon. Be weather aware just in case storms develop in your area.

Onto Sunday, well, as a strong upper level ridge builds expect a benign weather day. The main weather story for Sunday will be temperatures, with 700mb temps soaring to around 18 degrees C, expect highs to top out in the upper 80s west of I-25 and mid to upper 90s east of the corridor. What about the storm threat, well with dry air aloft and subsidence, storm initiation will have a hard time. This is due to the building ridge, so expect daytime convection to be minimal as a result. This is more a reality due to the lack of shear in the environment, so expect a pleasant Sunday across the CWA.

LONG TERM /MONDAY THROUGH FRIDAY/

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.

Monday we can expect cirrus cloud cover and some chances at isolated to scattered thunderstorms in the afternoon. A monsoon plume of moisture is expected to move in from the west and increase PWAT values. Subtle lifting from a shortwave may spark some high based convection. A substantial dewpoint spread at the surface will mean storms are going to be on the dry side. A risk of dry microburst is possible with the mentioned thermo profile and over 1000 J/kg of DCAPE available. Afternoon high temperatures look to be in the 80 in the inner basins and in the mid to high 90s out in the Nebraska Panhandle.

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 /18Z TAFS THROUGH 18Z SUNDAY/

Issued at 1122 AM MDT Sat Jul 4 2026

VFR conditions will prevail across all terminals for the duration of this TAF period. There is a chance, PROB30, for thunderstorms to impact KCYS, KBFF, and KSNY this afternoon. This activity will be brief and be out of the area by 00Z Sunday. Expect gusty and erratic winds in and/or near thunderstorms. No other aviation concerns for this forecast as winds will subside to less than 10 knots by 09Z Sunday.

CYS WATCHES/WARNINGS/ADVISORIES

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