409
FXUS65 KCYS 160556
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
1156 PM MDT Fri Aug 15 2025

.KEY MESSAGES...

- Isolated to widely scattered PM showers and thunderstorms will
  continue today and through the weekend with slightly cooler
  temperatures this weekend.

- Hot and dry conditions return for the upcoming work week with
  only minimal precipitation chances.

&&

.SHORT TERM /THROUGH SATURDAY NIGHT/...
Issued at 219 PM MDT Fri Aug 15 2025

A deep trough impacting the Northwest has shifted the mid and upper
level flow to the south/southwest pushing some weak energy northeast
across the CWA, this coupled with winds generally shifting to the
south is bringing in some low level moisture into southeast Wyoming
and the Nebraska Panhandle. This will increase the shower and
thunderstorm threat through the afternoon hours into the early
evening. Due to modest severe weather parameters, the primary threat
from these thunderstorms will be gusty winds in the 40 to 50 mph
range. Dewpoints will be 40 to 45 degrees across southeast Wyoming
and in the mid 50s across the Nebraska panhandle. With the
thunderstorm threat, kept POP values between 30 to 50 percent across
a good portion of the CWA. With the modest severe parameters in
place, all this should justify the Marginal severe risk for this
afternoon and early evening. Expect somewhat "cooler" temperatures
today with highs topping out in the 80s and low 90s primarily west
of the I-25 corridor and into the low to mid 90s across far eastern
Wyoming and the Nebraska panhandle.

Expect much of the same for Saturday, with another upper level
disturbance pushing through the CWA. Model agreement has improved
since earlier runs, showing similar placement and timing of the
energy. Kept POPs generally between 30 to 50 percent range.
Convective parameters once again are modest, with primarily  a wind
threat from any thunderstorm activity. Temperatures will continue a
slight downward trend through Saturday, which will be one of the
coolest days over the next week or so, with highs in the 80s to low
90s across most of the CWA.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 219 PM MDT Fri Aug 15 2025

Starting Sunday the Intermountain West starts to dry out as an upper
level ridge becomes centered on the four corners region of the
United States. Monday, the Intermountain west will be in a southern
flow helping to advect in some moisture for some possible isolated
thunderstorms in the afternoon and evening. These storms currently
appear to remain attached to the higher terrain so low pops were
added to those areas. Tuesday and Wednesday, the flow turns
Northwesterly advecting in warm dry air to really mitigate our storm
chances in the afternoon and evening. The high pressure system is
progged to remain over the four corners region through the week to
keep us mostly dry for the remainder of the week.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1144 PM MDT Fri Aug 15 2025

VFR conditions expected over the next 24 hours outside of any
thunderstorms which could bring reduced visibilities. Winds
should be calming as storms move out of the region, though an
occasional rare gust 15-20 knots could be possible. Otherwise
sustained speeds expected 5-10 knots. KRWL should gust again
tomorrow between 16-20Z. Storms expected to be possible again
tomorrow afternoon and evening all sites which could locally
impact winds and directions. Cloud decks should remain fairly
steady around 10k feet, but could fluctuate from local
precipitation or become clear at times.

&&

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

&&

$$

SHORT TERM...RZ
LONG TERM...MM
AVIATION...CG