064
FXUS65 KCYS 142336
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
536 PM MDT Tue Oct 14 2025

.KEY MESSAGES...

- Areas of locally dense fog may develop across southeast
  Wyoming and the Nebraska Panhandle late tonight into Wednesday
  morning.

- A storm system will move through the CWA late Wednesday
  through early Friday, first bringing showers and
  thunderstorms, followed by chances of mountain snow and strong
  winds.

- A few of the thunderstorms Wednesday afternoon may be strong
  to severe, of which they may produce small hail and gusty
  winds.

&&

.SHORT TERM /THROUGH WEDNESDAY NIGHT/...
Issued at 414 PM MDT Tue Oct 14 2025

Clearing skies along will continue for many locations across the
CWA into this evening as an upper level shortwave ejects
northward. Temps will be pleasant this afternoon/evening with
highs topping out in the upper 60s to lower 70s. Late tonight
into early tomorrow morning, dense fog and low ceilings may
affect portions of southeast Wyoming and the Nebraska Panhandle.
Attention in the short term then shifts to Wednesday afternoon,
as several factors will increase the severe weather threat,
primarily east of I-25 across eastern Wyoming and the Nebraska
Panhandle. Hence, this is why the Storm Prediction Center (SPC)
has us under a Marginal Risk (1 out of 5) for severe weather
with hail and strong winds being the main threat. Why, well,
first a surface low and associated warm front will push north,
bringing in a surge of 50+ degree F dewpoints across eastern
portions of our CWA. This is all ahead of a deep upper level
trough and associated closed low that will traverse the
Intermountain West into our region while an upper level ridge
pushes off to the east. The combination of the warm front
lifting north, bringing in copious amounts of moisture,
reflected by dewpoints, and daytime heating will work together
to destabilize the atmosphere. Other factors promoting the
possibility of severe weather is a 250MB jet maximum nosing into
our CWA along with decent deep-layer shear and sufficient
MUCAPE (1000 J/kg). Hi-res guidance is showing discrete cells
forming around 4PM, moving in a northeast direction, not only
the severe weather threat is there, but these cells could also
produce heavy rainfall if one were to go over your head. As
mentioned earlier in this discussion, one of the limiting
factors that may slow storm initiation is fog and the associated
cloud deck along with it, as all this is anticipated to form
where the greatest instability is. So, we will see how this
plays out, stay tuned...

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
Issued at 414 PM MDT Tue Oct 14 2025

An active end to the work week is expected as a strong trough moves
across Wyoming. By Thursday, a closed upper-level low will develop
within the trough, pushing across Wyoming throughout the day. The
track of this system will be from southwest to northeast, as a
result, much of the CWA appears to be in the warm sector ahead of
the cold front. South to southwest flow in the warm sector will
provide warm moist air which could spark some scattered showers and
thunderstorms ahead of the front. By Thursday afternoon, the front
will likely be through the CWA. Drier, cooler air will exist behind
the front, leading to high temperatures in the 40s, 50s, and 60s.
Similar high temperatures will persist on Friday as the back side of
the trough swings through the CWA.

Heading into Thursday night, the next round of high winds will
arrive. The cold front will cause MSLP gradients to tighten west of
the Laramie Range, which will in turn cause 700 mb winds to increase
up to 60 kts over the usual southeast Wyoming wind prones. Strong
subsidence will easily push these winds down to the surface. 60+ MPH
winds will be possible at Arlington, Bordeaux and the South Laramie
Range late Thursday night into Friday morning. Winds will gradually
decrease throughout the day Friday as the trough pushes away.

The weekend and the start of next week will be relatively uneventful
as a ridge of high pressure builds over the Rockies. Cool
temperatures will persist one more day on Saturday, but warm up on
Sunday. High temperatures on Sunday and Monday will range from the
upper 50s to low 70s which is above average for mid-October.
Subsidence under the ridge will keep skies mostly clear with minimal
precipitation chances.

&&

.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 535 PM MDT Tue Oct 14 2025

Moist southeasterly flow will cause low stratus and dense fog to
develop east of the Laramie Range this evening. Low stratus will
likely move in this evening while fog will develop a little later.
IFR conditions are expected due to poor visibility and low CIGs.
These conditions will likely continue through Wednesday morning
before lifting during the afternoon.

&&

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

&&

$$

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