265
FXUS65 KCYS 052324
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
524 PM MDT Fri Sep 5 2025

.KEY MESSAGES...

- Below average temperatures with lingering smoke possible on
  today.

- Warmer temperatures will develop for the Sunday through Friday
  period, with chances for isolated to scattered late day
  showers and thunderstorms nearly every day.

&&

.SHORT TERM /THROUGH SATURDAY NIGHT/...
Issued at 202 PM MDT Fri Sep 5 2025

Skies, based on visible satellite imagery, have cleared out nicely
across the CWA since this morning`s cloud cover. These clearer skies
will continue into and through the overnight hours, with 700 MB
temperatures dipping down into the low to mid single digits, expect
highs today only topping out in the 60s to low 70s with temperatures
falling relatively rapidly as the sun goes down this evening. Under
mainly clear skies tonight, temperatures will fall and by the time
you wake up tomorrow, you can expect to feel the upper 30s to lower
40s on your skin if you go outside. A few very isolated areas in the
Nebraska panhandle, far eastern Box Butte and Morrill counties, may
see patchy frost develop given calm, clear conditions overnight with
with lows bottoming out in the upper 30s. Any frost that develops
will likely be brief as temperatures rebound nicely through
Saturday, as ridging begins to nose into the CWA as the stout upper
level low that has been sitting near the Great Lakes Region,
influencing our weather here locally, begins to lift out and move
eastward. Highs are expected to climb into the 70s to low 80s while
lows dip into the mid 40s to lower 50s. Precipitation chances will
be minimal through the short term, but one can`t rule out a few
showers and/or storms developing over the higher terrain during the
afternoon hours primarily from the Laramie Range and west. The other
thing of note in the short term will be the smoke that dives south
from Canadian wildfires that will primarily affect western zones of
the CWA. Due to this, there is an air quality alert in effect
through 1PM Sunday for portions of western and northern Carbon
County. However, most of the CWA may see hazy skies with the
possibility of smoke aloft.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 202 PM MDT Fri Sep 5 2025

Sunday...As ridging aloft develops over our counties, return
southeast low level flow develops, advecting low and mid level
moisture across our counties, and producing scattered afternoon and
evening showers and thunderstorms, mainly west of I-25. The warming
trend continues with 700 mb temperatures near 13 Celsius.

Monday...The warming trend continues with low amplitude ridging
aloft and 700 mb temperatures rising to near 13 Celsius. With drying
at the low and mid levels, no precipitation is expected.

Tuesday...As the ridge aloft transitions over the Central Plains
states and our flow aloft turns southwest, temperatures will remain
about the same. Enough low and mid level moisture for isolated to
widely scattered late day showers and thunderstorms, mainly west of
I-25.

Wednesday...Southwest flow aloft strengthens, and with warm
temperatures aloft providing convective inhibition, only isolated to
widely scattered late day showers and thunderstorms will be
possible, mainly west of I-25. High temperatures about the same as
on Tuesday.

Thursday...South southwest flow aloft prevails, and with adequate
low and mid level moisture, we expect to see isolated to widely
scattered late day showers and thunderstorms. Perhaps slightly
cooler compared to Wednesday due to more clouds and precipitation.

Friday...As the shortwave trough aloft pivots into western Colorado,
the flow over our counties will turn southerly, advecting more low
and mid level moisture and clouds into our counties, and producing a
chance of late day showers and thunderstorms. With more cloud cover,
temperatures will be a bit cooler compared to Thursday.

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 521 PM MDT Fri Sep 5 2025

Northwest flow aloft will continue. Skies will be clear, with
smoke reducing visibilities to 6 miles at times at Rawlins until
18Z Saturday. Winds will gust to 23 knots at Chadron and
Alliance until 03Z.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...Air Quality Alert until 1 PM MDT Sunday for WYZ104-109-111>113.
NE...None.

&&

$$

SHORT TERM...RZ
LONG TERM...RUBIN
AVIATION...RUBIN