Area Forecast Discussion
Issued by NWS Cheyenne, WY

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955
FXUS65 KCYS 102038
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
238 PM MDT Thu Sep 10 2026

.KEY MESSAGES...

- Dry conditions expected through Friday alongside critical
  Fire Weather conditions.

- Moisture and cooler temperatures return for the weekend, with
  another shot of cooler air to start next week.

&&

.SHORT TERM /THROUGH SATURDAY NIGHT/...
Issued at 235 PM MDT Thu Sep 10 2026

Another dry, warm and windy day continues across the area. Red
Flag Warnings remain in place for the Laramie Range and westward
for relative humidity in the single digits and wind gusts up to
40 MPH. These conditions will continue through the evening
hours until the Red Flag Warning expires at 8 PM. Humidity
recoveries overnight are expected to be poor across most of the
forecast area. A shortwave entering Wyoming will increase winds
overnight, contributing to greater downslope, keeping surface
humidity from rising. For most of the CWA, the maximum humidity
overnight will stay under 30 percent.

Fire weather conditions continue into Friday, but shift further east
into the Nebraska panhandle. The aforementioned shortwave will
actually usher in a bit of mid-level moisture, raising relative
humidity enough to get clouds and maybe even a very light shower
early in the morning per Hi-Res guidance. Relative humidity out west
will stay above critical thresholds, however relative humidity in
the Nebraska panhandle will remain around 15 percent as the dry air
stays in place one more day. Red Flag Warnings are in effect for the
Nebraska panhandle for Friday afternoon. Windy conditions are
expected across the forecast area as zonal flow still persists. On
top of fire weather concerns, cannot rule out a few isolated showers
and thunderstorms developing later in the afternoon ahead of an
incoming cold front.

A cold front will move across the area Friday night, raising
relative humidity and bringing an end to fire weather conditions for
Saturday. Highs on Saturday will be cooler behind the front as 700
mb temperatures drop about 6C. Instead of highs in the upper 80s and
90s, most cities will have pleasant temperatures in the 70s.
Once again, cannot rule out some minor precipitation chances
behind the front, however instability and moisture are lacking.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
Issued at 235 PM MDT Thu Sep 10 2026

On Sunday an upper level system makes its way into the PNW. Guidance
is showing the potential for storms with this return flow ahead of
the upper level system`s passage. The main risk area for these
storms is east of I-25. Sunday night into Monday morning shows a
cold front passing over the CWA. After this front moves out, a ridge
starts to build, bringing cooler temperatures and dryer air. Some
storm and shower activity is possible Tuesday evening with return
flow. A shortwave passes through on Thursday evening, allowing the
ridge to continue to build. 700mb temperatures are in the 10-15C
range in this long term period. Temperatures start to cool off and
feel more like fall as the week progresses.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1131 AM MDT Thu Sep 10 2026

This afternoon, wind will become breezy over the WY terminals,
weakening in the evening and overnight. Wind over the NE terminals
will pick up this evening and into the morning hours, staying gusty
through tomorrow afternoon. Sky conditions are expected to be SKC,
with a FEW to SCT high level cloud decks moving in this afternoon
and evening. Otherwise, VFR conditions are expected for this TAF
period.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...Red Flag Warning from 11 AM to 7 PM MDT Friday for WYZ433.
     Red Flag Warning until 8 PM MDT this evening for WYZ419>429-
     432.
NE...Red Flag Warning from 11 AM to 7 PM MDT Friday for NEZ434>437.

&&

$$

SHORT TERM...SF
LONG TERM...ML
AVIATION...ML