textproduct: Cheyenne

KEY MESSAGES

- A plume of monsoon moisture will arrive today, moderating temperatures and improving rainfall chances through Wednesday.

- Marginal to Slight Risk of Severe Thunderstorms Monday through Wednesday. Strong gusty winds will be the primary threat.

- Heavy rainfall and localized Flash Flooding possible Tuesday through Wednesday night.

- More heat returns for Thursday through Monday, with some near record high temperatures possible for some locations and possible Heat Advisories.

SHORT TERM /THROUGH TUESDAY/

Issued at 216 PM MDT Mon Jul 27 2026

Tonight: WSR-88D radar reflectivity loop and model analysis shows scattered to possible numerous showers, isolated to scattered thunderstorms continuing through early evening, mainly east of I-25. Model trends show showers and some thunderstorms decreasing later tonight. Cloud cover will minimize cooling, acting like a blanket effect. The Storm Prediction Center has reduced the marginal and slight risk area for this afternoon and this evening which seems quite plausible due to extensive cloud cover and reduced instability. Storm movement will be enough to minimize heavy rain threat.

Tuesday: Looks like a more favorable day for scattered to numerous showers and scattered thunderstorms, especially with respect to thunderstorm intensity due to more solar insolation, better low level moisture supply and increased shear parameters, as evidenced by bulk shear values and projected 850/700 theta-e ridge axis placement. Concur with the Storm Prediction Center day 2 outlook showing marginal risk of severe thunderstorms to the right of a line from Laramie to Torrington to Scottsbluff. Marginal risk of flash flooding looks more likely due to weaker steering level winds around 700 mb, 10,000 feet MSL.

LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/

Issued at 216 PM MDT Mon Jul 27 2026

Wednesday: Positioning of decent 850/700 theta-e ridge axis, and the proximity of a more decent shortwave trough aloft near peak heating, at least for late July, and the Precipitable Water (PWAT) values from 1.5 to 2 inches, along with impressive shear and instability suggests another round of scattered to numerous afternoon and evening showers and scattered thunderstorms, with a marginal risk of severe thunderstorms to the right of a line from Laramie to Casper in the afternoon and evening from the meteorologists at the SPC, Storm Prediction Center.

Thursday through Monday: Monsoonal moisture retreats out of our County Warning Area (CWA) as a drier and hotter air mass returns producing nearly dry conditions with only minimal chances for isolated to scattered thunderstorms over and near our Snowy, Sierra Madre, and Laramie Ranges due to differential orographic processes. Temperatures will soar once again, especially for Sunday and Monday, with some locations possibly approaching near record maximum temperatures, and perhaps the long standing all time record high temperature of 100 degrees at Cheyenne, that has been achieved four times, the most recent in the 1950s.

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/

Issued at 1155 AM MDT Mon Jul 27 2026

Primarily VFR conditions will prevail through the TAF period. The only exception will be after 03Z where MVFR conditions may be in place for KSNY and KAIA where showers are most likely to develop, dropping cigs to 2-3 kft. Confidence isn't high regarding shower and thunderstorm coverage this afternoon given the current ongoing showers which are delaying heating and destabilization, so further convective initiation will depend on how quickly we can recover. Any high-based showers and thunderstorms that are able to develop will have the potential to produce gusty and erratic winds up to 45 knots, especially given DCAPE greater than 1000 J/Kg and forecast soundings showing inverted-v profiles. Outside of the deeper convection, expect the typical diurnal onset of cumulus which will dissipate shortly after sunset.

CYS WATCHES/WARNINGS/ADVISORIES

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