015
FXUS65 KCYS 070533
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
1133 PM MDT Mon Oct 6 2025

.KEY MESSAGES...

- Freeze Warnings and Frost Advisories are in effect for
  portions of southeast Wyoming and western Nebraska Tuesday
  morning.

- Warmer, drier conditions return mid-week.

&&

.SHORT TERM /THROUGH TUESDAY/...
Issued at 322 PM MDT Mon Oct 6 2025

A dreary day continues across most of the forecast area with cool,
below average temperatures and widespread cloud cover. Visible
satellite imagery shows a blanket of low stratus for most areas
east of the Laramie Range, but partial clearing is beginning to
take place in Carbon County and some of the northern zones. With
some upper-level energy still lingering over the CWA, cannot
rule out a few isolated light showers this afternoon, but, more
than likely, most areas are done with precipitation for the day.

Heading into tonight, clearing will continue, with clouds expected
to clear out of a majority of the forecast area. With the
upper-level trough slow to move out, clouds will likely linger
around and just north of the Interstate 80 corridor between
Laramie and Sidney. Due to the cloud cover, these areas will
likely stay a tad bit warmer than other areas with lesser
chances for the development of frost, however cannot rule out
some patchy frost in isolated areas. The rest of the CWA is
likely to see clear and calm conditions overnight. As a result,
temperatures will tank due to efficient radiational cooling,
especially in southeast Wyoming. Areas west of the Laramie Range
as well as Converse and Niobrara Counties will likely see
widespread frost and temperatures below freezing overnight.
Freeze Warnings remain in effect for portions of southeast
Wyoming that have not yet seen a freeze this season. The frost
potential will also spread into areas further east. The northern
Nebraska panhandle and northern Goshen County will likely see
frost develop overnight with calm and clear conditions as well
as higher humidity. Issued a Frost Advisory for these areas as
sensitive vegetation could be affected despite temperatures not
reaching freezing.

By Tuesday, weak ridging will begin to move into the Rockies,
causing temperatures to warm. Cold morning temperatures will
warm quickly, with highs climbing into the 50s and 60s as 700 mb
temperatures above 0C return to the CWA. Subsidence under the
ridge will keep precipitation chances at bay with most locations
expected to have mostly sunny skies throughout the day. Heading
into the overnight hours, low temperatures will return to
seasonable for the beginning of October.

&&

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
Issued at 322 PM MDT Mon Oct 6 2025

At the start of the long term, a weak upper level trough and
associated shortwave pushes through our CWA, with little to no
moisture in the mid-levels, precipitation chances will be minimal.
This will quickly be replaced by an upper level ridge that builds
north into our area late Wednesday, bringing relatively benign
weather across most of our CWA through Friday. However, a weak
shortwave will slide across the region and increase chances of
precipitation primarily for our western zones Friday into Saturday.
All this is ahead of a deep upper level trough that moves into the
West Coast Saturday and progresses east into our CWA by Sunday then
quickly exiting to the northeast on Monday. Most of the energy, at
this time, appears to skirt just to our north which keeps most of
the precipitation chances out of our area. So, what about
temperatures, with the upper level ridge building across our CWA
Wednesday and Thursday, this will bring warmer 700 MB temperatures
in the 5 to 8 degree Celsius range which will result in surface
temps climbing into the 60s west of I-25 and 70s to the east for
Wednesday. Expect slightly warmer temps for Thursday into Saturday
with highs topping out in the 70s and 80s, highest across eastern
Wyoming and the Nebraska Panhandle. A sign that winter is coming,
overnight lows through the long term period will dip into the 30s
and 40s.

&&

.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 1131 PM MDT Mon Oct 6 2025

The main aviation concerns through Tuesday morning will be
patchy low clouds and fog. Confidence is highest in fog leading
to IFR to LIFR conditions at KLAR. Flight reductions are also
favored at KCYS and KAIA, but confidence is lower here. Local
fog and/or low clouds around other terminals cannot be ruled
out, but the probability is too low to add to the TAF at this
time.

Expect improving conditions through the morning, reaching VFR at
all terminals by midday. Winds will remain light for most of the
period, but southeast winds may begin to increase again near
KLAR and KCDR towards the end of the period.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...Frost Advisory until 9 AM MDT Tuesday for WYZ108.
     Freeze Warning until 9 AM MDT Tuesday for WYZ101-102-104-110-
     111.
     Dense Fog Advisory until 8 AM MDT Tuesday for WYZ116.
NE...Frost Advisory until 9 AM MDT Tuesday for NEZ002-003-095-096.

&&

$$

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