498
FXUS65 KCYS 251129
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
429 AM MST Tue Nov 25 2025

.KEY MESSAGES...

- A High Wind Warning is in effect for the northern counties of
  the Nebraska Panhandle until 2 PM. High winds look possible
  for some of the southeast Wyoming wind prones on Wednesday.

- Colder temperatures expected through much of the week behind a
  cold front.

- The probability of an arctic cold front is increasing for
  next weekend which will usher in very cold temperatures and
  accumulating snowfall.

&&

.SHORT TERM /THROUGH WEDNESDAY NIGHT/...
Issued at 316 AM MST Tue Nov 25 2025

With the cold front through the CWA early this morning, winds have
begun to turn more northwesterly, allowing high winds to weaken.
Winds have dropped below 50 MPH gusts in the South Laramie Range and
foothills, while winds at a few isolated sites in the Arlington zone
continue to gust above 50 MPH. However, the frequency and intensity
of these gusts are gradually decreasing, with an on time expiration
of these High Wind Warnings likely at 5 AM this morning. Winds
in the Nebraska panhandle have also weakened early this morning.
This is not unusual as it is hard to get high winds in the
panhandle overnight due to lack of strong subsidence. Chadron
Airport did briefly gust 59 MPH earlier overnight, but has not
gusted since.

Northwest flow will dominate throughout the day with an upper-level
250 mb jet progged to position itself over the CWA. This jet will
help facilitate stronger wind gusts after sunrise across the
northern Nebraska panhandle where High Wind Warnings are in place.
Strong low-level winds will also be in place from a strong surface
low over South Dakota. 800 mb winds will max out around 60 kts with
decent subsidence. However, it looks like the strongest subsidence
will not be co-located with the strongest winds aloft, which could
pose issues for getting high winds at the surface. Regardless, a
High Wind Warning remains in effect until 2 PM this afternoon, with
the strongest winds expected between 6 AM and noon. Besides wind,
the weather will be rather uneventful today with precipitation
chances at a minimum as the trough axis pushes eastward into the
center of the country. Behind the front, temperatures will be much
colder. Highs will only be in the 30s for most cities, which is
anywhere from 5 to 10 degrees below average for late November.
Expect chilly temperatures to continue overnight.

Early Wednesday morning, winds will begin to increase over some of
the usual southeast Wyoming wind prones. An approaching upper-level
disturbance will cause 700 mb CAG to CPR gradients to increase to
over 60 meters, which is usually an indicator of high winds around
the Arlington area. MSLP gradients appear to have no response from
the upper-level disturbance. Winds aloft, however, will increase to
about 55 kts with decent subsidence. High winds look most likely at
Arlington and possibly the South Laramie Range Wednesday morning
into Wednesday afternoon. This disturbance will also bring a bit of
mid-level moisture, which could lead to some scattered light snow
showers developing across the CWA during the day Wednesday.
Accumulation does not look likely at this time, with Hi-Res guidance
showing only very light precipitation.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
Issued at 321 PM MST Mon Nov 24 2025

Long term will be active thanks to a quick moving shortwave
trough during the mid-week timeframe that will bring some gusty
winds and light mountain precipitation, but the real story is
this weekend when a deep trough in the Western US will
absolutely plummet temperatures with widespread highs below
freezing and overnight lows into the single digits to end
November and bring in the start of winter in December.

To start the long term, we`ll be under northwesterly flow aloft
from a ridge over the Western US that will shift over the region
through Friday. Wednesday should start off a bit blustery due to
a weak shortwave aloft passing along the periphery of the CWA,
and we may even see near to high winds for the Arlington wind
prone region, but outside of this we should stay just outside of
high wind criteria for the majority of our area. A few mountain
or high terrain snow showers may also occur thanks to this
system, but with flow upslope over the western side of the
region and moisture on the low side, this should only produce a
few light amounts early on before moving out of the region.
Moving into the remainder of the week, benign conditions are
expected under ridging through early Friday.

But moving into the weekend, we`ll see a noteworthy pattern
change as models indicate a shortwave should move across on
Friday, followed by a very deep trough overtaking the Western US
into Saturday with a cold airmass accompanying this system as
we move into the last couple of days of the month. There`s still
some variation on the strength and exact placement of this
system with ensemble clusters showing a few variations of this
feature, but all in agreement on the trough taking over the
West, leading to high confidence in the pattern change but
low to moderate confidence in the exact outcome for our area.
What we expect currently is multiple waves of precipitation with
temperatures cold enough to produce widespread snow beginning
as early as Friday morning and continuing through the start of
next week before moisture finally exits. With the uncertainty
currently expected, getting amounts pinpointed this far out is
difficult at best, but current estimates would place several
inches for all of our zones by Monday morning. Meanwhile
widespread temperatures at or below freezing will begin Friday
afternoon/evening and last through early next week as well, with
the coldest day expected on Sunday as widespread highs in the
20`s with a few 30`s possible and lows into Monday morning
almost widespread single digits. As mentioned though there
remains a bit of uncertainty, and the NBM is showing a spread in
Cheyenne for example of around 17 degrees for our afternoon
high Sunday, indicating we could be as "warm" as 29 degrees or
as cold as 12 for the day! But no matter where we land, this
will be the coldest we`ve seen for the year, so everyone should
be prepared for winter to make itself known as we move into the
post-holiday timeframe.

&&

.AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 429 AM MST Tue Nov 25 2025

The main aviation concern today will be strong, gusty winds. The
Nebraska panhandle terminals will likely see the strongest gusts
today with gusts over 40 kts possible. Gusts over 30 kts will be
possible in southeast Wyoming. Winds will ease this evening,
becoming light and variable at most terminals.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...High Wind Warning until 5 AM MST early this morning for WYZ110-
     116-117.
NE...High Wind Warning until 2 PM MST this afternoon for NEZ002-003-
     095-096.

&&

$$

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