textproduct: Cheyenne

KEY MESSAGES

- Warmer and drier conditions will continue through Friday.

- Precipitation chances return over the weekend.

SHORT TERM /THROUGH FRIDAY/

Issued at 123 PM MDT Wed Aug 19 2026

The rest of the afternoon is expected to be quiet as upper-level ridging builds over the Great Basin. Cannot rule out a stray shower or thunderstorm headed into the evening hours as a cumulus field continues to build over the high terrain and areas out west. However, most Hi-Res models keep precipitation south of the Wyoming/Colorado border. Quiet conditions will continue overnight, with a low chance of fog and low stratus developing early Thursday morning as winds turn southerly and increase dewpoints.

Another benign day is in store for Thursday as the ridge strengthens and gradually shifts eastward towards the Rockies. As a result, mostly sunny skies are expected with warming temperatures. High temperatures will rise about 5 to 8 degrees compared to today's temperatures. This means a return to 90 degree temperatures for most locations east of the Laramie Range. The ridge will do a good job keeping precipitation chances minimal, however, there are a few Hi- Res models that show isolated showers moving into the western zones during the evening hours. The main concern with these showers will be sudden, gusty winds. Any showers that do develop will dissipate by midnight, with calm conditions expected for the remainder of the overnight.

Overall, Friday looks similar to Thursday albeit a bit hotter as the ridge continues to strengthen and shift further into Wyoming. A few locations east of the Laramie Range could see the low 100s, however most high temperatures will be in the 90s. Precipitation chances remain low but not zero as model sounding show decent amounts of instability.

LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/

Issued at 123 PM MDT Wed Aug 19 2026

Saturday...With the upper ridge axis, near 500 mb, or 18,000 feet MSL, transitioning into the western Great Plains states from the Dakotas southward to eastern Colorado, west southwest flow aloft will develop over our counties, helping the pseudo monsoonal moisture to creep back into our forecast area from western Colorado through primarily our western counties west of I-25. Afternoon thunderstorms will be most prevalent across our Snowy, Sierra Madre and southern Laramie ranges, with evening thunderstorms, isolated to widely scattered, spreading across our entire forecast area, with of course the greatest areal coverage over our mountainous zones due to differential and orographic effects. With additional cloud cover and precipitation coverage, high temperatures will be tempered somewhat despite the warm mid level temperatures.

Sunday...More scattered beneficial showers and thunderstorms will occur in a carbon copy type day compared to Saturday, with broad west flow aloft over southeast Wyoming and western Nebraska, and pseudo monsoonal moisture over the counties. Carbon copy day temperature wise, as temperatures climb a few more degrees.

Monday...Looks like the best chance for measurable rainfall, of 0.01 inch or more, with scattered to numerous afternoon and evening showers, and scattered thunderstorms due to increased monsoonal moisture, light steering winds and PWATs, Precipitable water increases. Slight cooling in maximum temperatures due to lowering of mid level temperatures and additional cloud and precipitation coverage.

Tuesday...Ridging aloft amplifies over the Rockies, though with monsoonal moisture trapped under the ridge from western Colorado through the western half of Wyoming, and to a lesser coverage over eastern Wyoming and western Nebraska, expect to see another carbon copy type day with scattered to numerous showers, and scattered thunderstorms during the afternoon and evening hours. Similar maximum temperatures compared to Monday, with clouds and precipitation coverage tempering highs, with readings peaking in the 80s to lower 90s.

Wednesday...Similar day to Tuesday, with the ridge axis from eastern Montana through central Colorado. Monsoonal moisture will be trapped underneath the ridge aloft, though shower and thunderstorm coverage will be more limited due to warm temperatures aloft.

AVIATION /00Z TAFS THROUGH 00Z FRIDAY/

Issued at 522 PM MDT Wed Aug 19 2026

VFR conditions over the next 24 hours with very few clouds at high levels or just clear CIGs through the period. Winds become light and remain that way through the next 24 hours, generally 10 knots or less and mostly variable as all sites see shifting conditions through the period.

CYS WATCHES/WARNINGS/ADVISORIES

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