190
FXUS65 KCYS 311150
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
550 AM MDT Sun Aug 31 2025

.KEY MESSAGES...

- Drier conditions expected to return Sunday and through much
  of next week.

- Warming trend starts late this weekend with temperatures
  closer to seasonal averages through Tuesday.

&&

.SHORT TERM /THROUGH TUESDAY/...
Issued at 245 AM MDT Sun Aug 31 2025

Current observations across the area early this morning
indicating some cool temperatures across southeast Wyoming with
readings in the low to mid 40s under clear skies. Feeling a
little fall-ish for the Laramie Valley with Laramie at 43
degrees. May see a few locations in the upper 30s for lows by
sunrise. Slightly warmer temperatures are expected Sunday
afternoon as the upper level ridge across the eastern Great
Basin nudges eastward into western Colorado and Wyoming today.
However, slightly cooler than normal temperatures will continue
for the final day of August with highs in the 70s for most of
the area...and low 80s along and near the Platte River valley.
Otherwise, could see some patchy fog early this morning for
Dawes, Sioux, and Box Butte counties. Any lingering fog should
lift shortly after sunrise.

All models show drier conditions lingering through Monday and
likely Tuesday for most of the region. Models show an upper
level high forming near the Four Corners region late Sunday and
into Monday. This high is forecast to drift northward into Utah
by Tuesday. Although mid to upper level flow will remain light
out of the north or northwest, a warming trend is still expected
for Wyoming and western Nebraska. Highs will return to the upper
70s to mid 80s early next week...warmest across the lower
elevations of far eastern Wyoming and western Nebraska. This is
roughly where it`s suppose to be for this time of the year. Dry
conditions will remain for most of the area, but can`t rule out
a few thundershowers for the mountains Tuesday afternoon.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
Issued at 305 AM MDT Sun Aug 31 2025

Rather quiet for the long term as most models show the stubborn
upper level ridge remaining near the forecast area. Models and
ensembles still struggling with the midweek cold front coming
out of Canada, but are starting to come into better agreement
with the eastward position. However, ensemble spreads still
remain significant as we head into Wednesday and Thursday.
Increased temperatures a few degrees on Wednesday with highs in
the 70s for most of the area and a few upper 60s for the
northern Nebraska Panhandle. Thursday morning will feel like
autumn has arrived with widespread low to mid 40s for far
eastern Wyoming and western Nebraska, due to clear skies and a
pretty dry airmass over the plains. With the upper level ridge
axis nearby, afternoon temperatures will recover with highs in
the 70s and low 80s by late this week. Precipitation chances
appear limited due to the dry airmass and limited instability,
but the best chance for showers and an isolated thunderstorm
will be Wednesday and Friday afternoon.

Further out, the GFS and ECMWF both show the eastern Pacific
becoming more active as a potent upper level trough digs
southeast across the Pacific Northwest. Will keep an eye on this
system with some pretty chilly air moving southeast across Idaho
and Montana by September 7th-9th.

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 550 AM MDT Sun Aug 31 2025

Upper level ridge axis will slide east into western and central
Wyoming over the next 24 hours. Drier conditions are expected with
some patchy fog possible over portions of western Nebraska.

HAZARDS/WEATHER TRENDS: VFR conditions will prevail for the
southeast Wyoming terminals through Sunday evening with northwest
winds around 15 to 20 knots this afternoon. For western Nebraska
terminals, low-end MVFR CIGS and IFR CIGS are expected until 15z,
mainly for KAIA and KCDR. Can`t rule out IFR CIGS for KSNY and KBFF
early this morning, but confidence is low with sunrise expected
shortly. There is a chance of additional IFR CIGS late tonight after
06z Monday for KAIA and KCDR.

&&

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

&&

$$

SHORT TERM...TJT
LONG TERM...TJT/RZ
AVIATION...TJT