FXUS65 KCYS 230525
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
1125 PM MDT Sat Aug 22 2026

.KEY MESSAGES...

- Scattered to numerous showers and thunderstorms expected this
  weekend, with the possibility of widespread rain on Saturday.
  A few strong to marginally severe thunderstorms possible
  Saturday afternoon. Flash flooding is also possible.

- Daily shower and thunderstorm chances continue Monday through
  the end of the week with slightly above average temperature 
  expected until Thursday.

&&

.SHORT TERM /THROUGH SUNDAY NIGHT/...
Issued at 130 PM MDT Sat Aug 22 2026

Another active day is expected this afternoon and evening as a 
shortwave passes through the upper-level ridge, bringing with it a 
push of monsoon moisture. Much like yesterday, the early development 
already being seen is weak and pulsey due to a decent amount of 
MLCIN still present. As the afternoon progresses, CIN will erode and 
storms will take advantage of the ample amounts of SBCAPE that the 
RAP is predicting later this afternoon. The shortwave will provide 
the lift for storms to develop while decent shear will allow for a 
few organized cells to sustain themselves. For the most part, 
hodographs are fairly linear, so multicell clusters and perhaps a 
small line or two are the favored storm modes. This is supported by 
Hi-Res guidance showing a similar solution. Although strong winds 
will be the primary concern in storms, embedded large hail could 
also be possible. With the monsoon push, PWATs are in the 90th 
percentile with model soundings showing rather slow cloud layer 
winds. As a result, heavy rains are expected with flash flooding a 
possibility. Along with flash flooding, a few severe thunderstorms 
cannot be ruled out. Although storms are already beginning to fire, 
the strongest storms are most likely 4 PM and 9 PM this evening. 
After this timeframe, linger scattered showers are expected 
throughout southeast Wyoming and western Nebraska for the better 
part of the overnight. With the remnant moisture from storms and 
weak southerly flow overnight, patchy fog and low stratus could once 
again be possible for areas east of the Laramie Range, including the 
Nebraska panhandle.

Sunday does not look as active as Saturday, although precipitation 
chances are still forecast. The ridge will flatten slightly as a 
trough skirts the Canadian border. This will cause winds to turn 
more westerly, which will help dry the low-levels a bit compared to 
Saturday. The westerly winds also cut down on instability, with 
model soundings only showing about 1000 J/kg of CAPE. As a result, 
Hi-Res guidance shows less coverage of storms across the forecast 
area. Any storms that develop on Sunday are not likely to be severe. 
With the westerly winds, gusty conditions are expected out west. A 
decent MSLP gradient will set up with 40 kt winds aloft. This could 
lead to 40+ MPH wind gusts during the afternoon and evening hours. 
Winds as well as any showers will dissipate overnight.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Issued at 130 PM MDT Sat Aug 22 2026

Moving into the work week we'll start off on the hot side with a
high pressure ridge firmly in control of the Western US. While
temperatures will cool just a couple of degrees compared to
Sunday, highs still sit warmer than average by around 5-8
degrees. A cold front will be approaching the region with
another round of afternoon showers and thunderstorms on tap
including locally stronger to weakly severe activity possible.
By Tuesday though a backdoor cold front will offer very meager
respite as highs drop by around 2-6 degrees, closer to near
average but still above by up to a few degrees. Similarly, 
moisture will continue to remain just above average at around 
120-140% of average, equating to PWAT values of0.75-1.25 
inches. While not impressive by any stretch of the imagination, 
this should continue to fuel daytime thunderstorms with a 
marginal risk of severe activity. Wednesday through the end of 
the week look to be largely similar with a steady warming trend,
bringing us back to temperatures similar to Monday alongside 
continued daily afternoon thunderstorm risk under westerly to 
northwesterly flow. Drier air will slowly infiltrate through the
week though, and this will begin to steadily increase our fire 
weather risk with elevated conditions at least by Friday. Anyone
expecting an early end to summer will be sorely disappointed in
the last full week of August.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 1125 PM MDT Sat Aug 22 2026

Showers and thunderstorms will push east through the CWA for the 
next hour or so and mainly impact KSNY. These storms may lead to 
lower CIGs and VIS. Then, through the overnight hours, clouds will 
lift and clear through tomorrow, bringing a return of VFR 
conditions by the end of this TAF forecast. Breezy winds with 
gusts 15-25 knots are possible across most terminals except KBFF
and KCDR at various times for this TAF period.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...None.

&&

$$

SHORT TERM...SF
LONG TERM...CG
AVIATION...RZ