textproduct: Cheyenne

KEY MESSAGES

- Marginal risk of severe thunderstorms through early this evening for the western half of the Nebraska Panhandle, with a slight risk of severe thunderstorms for the eastern half of the Nebraska Panhandle in our forecast area.

- Red Flag Warning has been issued for portions of southeast Wyoming for gusty winds and low relative humidities starting Tuesday at noon through 9pm Tuesday Night.

- Cooler on Wednesday and especially for Thursday through Saturday, with increasing chances for afternoon and evening showers and thunderstorms.

SHORT TERM /THROUGH TUESDAY NIGHT/

Issued at 211 PM MDT Mon Aug 10 2026

Tonight...Challenges tonight will be possibilities of isolated to scattered thunderstorms through early evening, along with the possible few strong to severe thunderstorms over the Nebraska Panhandle through early evening. The Storm Prediction Center in Norman, Oklahoma has trimmed back the marginal risk of severe thunderstorms to the eastern half of the Nebraska Panhandle, with a slight risk of severe thunderstorms that includes our Cheyenne County of the southern Nebraska Panhandle, including Sidney.

The 16Z HRRR run shows isolated to widely scattered thunderstorms developing around 20Z, roughly to the right of a line from Laramie to Torrington to Scottsbluff, with isolated strong to severe thunderstorms developing across the southern Panhandle Counties of Kimball and Cheyenne, including Sidney through late afternoon. This seems quite plausible considering the impressive 850/700 mb theta-e ridge axis developing across the southern Nebraska Panhandle, along with CAPE values from 600 J/kg over eastern Kimball County up to 2800 J/kg over eastern Cheyenne County, combined with bulk shear values near 35 knots. As per the SPC discussion, the primary threats from any severe storms will be wind gusts in excess of 60 mph, with a smaller threat for hail. Most thunderstorms should end by 01Z according to the latest HRRR run. Outside of the southern Nebraska Panhandle, thunderstorms will be capable of producing gusty winds due to the steep adiabatic lapse rates. Expecting clouds to clear out after early evening with a quiet night on tap.

Secondarily, the Red Flag Warning looks on track until mid evening for much of southeast Wyoming except for the far southeast.

Tuesday...Relatively weak westerly flow aloft prevails, with a shortwave trough aloft moving across our counties near peak heating. With the NAM indicating a decent plume of low and mid level moisture by late afternoon stretching from southern Albany County into the southern Nebraska Panhandle, expecting isolated to widely scattered thunderstorms to form near the cap weakness over and near our Snowy, Sierra Madre and southern Laramie Ranges, including the Laramie Valley and western and central Laramie County including Cheyenne.

Used a blend of the MET MOS and AVN MOS for maximum temperatures which will range from the upper 80s to lower 90s west of I-25, with mid 90s to near 105 east of I-25, with the hottest temperatures over the northern and central Nebraska Panhandle.

Will need to keep an eye on the necessity of another Red Flag Warning for late morning into the early evening hours primarily where decent winds and low relative humidities will coincide over much of the northern Laramie Range and Converse County.

Tuesday night...With the loss of daytime heating, and lack of significant lifting mechanisms, it looks like isolated to widely scattered thunderstorms/convection should dissipate around sunset, with a tranquil, quiescent overnight expected thereafter.

AVIATION /12Z TAFS THROUGH 12Z TUESDAY/

Issued at 525 AM MDT Mon Aug 10 2026

This TAF period brings chances of showers/thunderstorms to all terminals this afternoon. These showers/storms will bring variable, gusty winds between 35-40 knots. The WY terminals will mostly see westerly to northwesterly winds, and the NE terminals will see mainly variable winds early in the afternoon, with gusts out of the west in afternoon storms. WY terminals can expect to see gusty showers with little rain and the SNY and AIA terminals have chances for stronger thunderstorms. Once the showers/storms move out of the area, winds are expected to return to around 10 knots across most terminals, and clouds will mainly be scattered to broken. VFR conditions are expected through this TAF period however, visibility may drop below 3sm under the strongest storms but most of the time should stay around 5 to 6sm.

AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/

Issued at 959 PM MDT Mon Aug 10 2026

VFR will remain through the TAF period under mostly dry conditions and 5-10 knot southerly flow. There is a chance for some low clouds at KAIA below 5 kft around sunrise, however confidence isn't high enough to include a PROB30 group for the potential for brief MVFR cigs. Expecting less storm coverage tomorrow afternoon with PoPs of 15-20% for mainly the Wyoming terminals, therefore have left VCSH due to the spotty coverage. Any gusty showers/storms will produce little to no rain and gusts up to 40 knots. Again, confidence in coverage or terminal impacts is low at this time (<20%). Can expect WSW gusts peaking from 20-25 knots for the Wyoming terminals beginning in the late morning and early afternoon.

CYS WATCHES/WARNINGS/ADVISORIES

WY...Red Flag Warning from noon to 9 PM MDT Tuesday for WYZ417>430. NE...None.