671
FXUS65 KCYS 240012
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
612 PM MDT Thu Jul 23 2026

.KEY MESSAGES...

- Scattered showers and thunderstorms will continue through the
  evening. Localized flash flooding remains possible.

- Warmer air will return to the area Friday into early next
  week. Near record high temperatures are possible Saturday
  through Monday.

- Dry weather is expected Friday with a few isolated storms
  Saturday and Sunday. Monsoon moisture will return Monday and
  increase thunderstorm chances thereafter.

&&

.SHORT TERM /THROUGH FRIDAY NIGHT/...
Issued at 146 PM MDT Thu Jul 23 2026

The upper level ridge is still feeding the Intermountain West some
monsoonal moisture from the central Pacific. Coverage is starting
become more active with scattered showers and few thunderstorms
popping up across the forecast area. Unlike yesterday widespread
rainfall is not expected with these weak showers but localized heavy
rainfall is still possible under the stronger thunderstorms. The
weather threat looks limited today, but gusty outflow winds between
60 to 65 mph can`t be ruled out as the updrafts in the stronger
thunderstorms start to collapse. The primary concern remains
frequent lightning and isolated heavy rainfall with some flooding
potential. The Flood watch is still expected to expire at midnight
tonight. Hi-res guidance has pretty good consensus of shower
development decreasing quite rapidly after 6pm with any lingering
storms/showers to be either moved out of the area or dissipated
around 11pm.

The ridge aloft will amplify across the Rockies on Friday into the
weekend, leading to another round of heat. Areas west of I-25 will
be in the 80`s and 90`s tomorrow while areas east of I-25 is
expected to be in the 90`s. Temperatures are expected to be in the
90`s and 100`s by Saturday with the core of central high pressure
moving back west to the four corners region. This will result in a
robust capping inversion around 550-mb per forecast soundings, which
will put a strong cap on thunderstorm activity. Overall, expect
little to no afternoon showers and thunderstorms Friday and through
this weekend.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
Issued at 146 PM MDT Thu Jul 23 2026

Saturday through Wednesday...Isolated to scattered afternoon and
evening showers and thunderstorms expected, with areal coverage
increasing each day due to increased mid level moisture.
Fortunately, more beneficial rains expected concentrated over and
near our Snowy, Sierra Madre and Southern Laramie Ranges, with the
best chances for convection on Monday through Wednesday. Typical
weak northwest flow aloft on the northeast periphery of the ridge
aloft will aid in occasional passing shortwave troughs aloft near
peak heating resulting in increasing convective potential each
day.

&&

.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 603 PM MDT Thu Jul 23 2026

A shortwave trough aloft, also known as a weather disturbance
aloft, moves to eastern Wyoming by early evening, then to
western Nebraska by midnight, and interacts with a moist low and
mid level atmosphere to produce scattered to numerous showers,
and scattered thunderstorms into this evening, most
concentrated along and east of Interstate 25. A drier and warmer
airmass will then spread across the region late tonight and on
Friday.

Wyoming TAFS...HRRR and WSR-88D radar and NAM model indicates
that widely scattered showers and thunderstorms should end by
02Z across southeast Wyoming, thus confidence is high enough to
include TEMPOs at KLAR and KCYS, producing wind gusts to 35
knots. A secondary round of widely scattered showers and
thunderstorms will likely develop across Albany and Laramie
Counties, according to the HRRR, from 00Z to 03Z. Then skies
will clear out with VFR prevailing. As is common, expect gusty
diurnal winds until sunset.

Nebraska TAFS...HRRR and the NAM show an initial round of
scattered showers and thunderstorms affecting the central and
southern Panhandle until 02Z or 03Z, and thus confidence is
high enough to include PROB30s at both Scottsbluff and Sidney,
with the strongest storms producing erratic wind gusts to 45
knots as well as brief MVFR ceilings and visibilities. WSR-88D
radar reflectivity suggests thunderstorms unlikely at KCDR and
KAIA. Skies will clear out later tonight with VFR prevailing.
Expect the typical gusty diurnal winds until sunset.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...Flood Watch until midnight MDT tonight for WYZ101>119.
NE...Flood Watch until midnight MDT tonight for NEZ002-003-019>021-
     054-055-095-096.

&&

$$

SHORT TERM...MM
LONG TERM...RUBIN
AVIATION...RUBIN