Rawlins, Wyoming 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

124
FXUS65 KCYS 061805
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
1205 PM MDT Tue Oct 6 2026

.KEY MESSAGES...

- Dry conditions and above average temperatures will continue
  through the work week.

- A pattern change is increasingly likely beginning around this
  weekend into early next week, but the details remain
  uncertain.

&&

.SHORT TERM /THROUGH WEDNESDAY NIGHT/...
Issued at 1205 PM MDT Tue Oct 6 2026

Another day of anomalously warm conditions across SE Wyoming and the
Nebraska Panhandle, with multiple locations expected to see record
high temperatures for this time of year. We remain under upper-level
ridging in a quiescent pattern, with a 100 knot polar jet located
well to our north over the Canadian Prairie provinces, resulting in
mostly dry conditions over our area. Current mid-level water vapor
imagery shows a weak disturbance located over Central Utah, with
proximity radar indicating some showers over the region and some
elevated instability above 600 mb on the 12Z KSLC sounding. The bulk
of the forcing for ascent associated with this low-amplitude
shortwave trough is expected to remain mostly to our south over
Colorado as the wave lifts north and east, however cannot rule out a
few high-based showers over the Snowy and Sierra Madre Ranges later
this afternoon. Forecast soundings south of the I-80 corridor in
Wyoming indicate inverted-v signatures, with rather meager MLCAPE
around 100 J/Kg, so definitely thinking that someone over the higher
terrain will see a weak shower, but any activity will produce far
more wind than any beneficial rainfall. Didn`t increase PoPs enough
to message in deterministic wording for showers in the forecast
because almost everyone is expected to see no rain, with any virga
showers resulting in little to no precipitation thanks to near 40F
spreads at the surface.

Now...for the heat. At the time of this discussion, stations along
the I-80 corridor in SE Wyoming are rapidly warming up, with
Cheyenne already up to 80F before noon. Thanks to the lack of clouds
and the very dry air mass with surface dewpoints currently in the
20s to low 30s, we should easily tie if not break the record at
KCYS, which stands at 83F set back in 2020. Laramie also has a
decent shot at breaking their record of 77F set back in 1975 thanks
to 700 mb temperatures ranging from the 90-95th percentile relative
to climatology over SE WY. Our Nebraska locations will likely fall
just short of record criteria as slightly richer low-level moisture
is present at this time, resulting in overall slower surface
heating. While high-resolution ensemble guidance has median minimum
RH values ranging from 15-20%, red flag conditions are not
anticipated at this time due to overall winds of 5-15 mph and gusts
remaining below 25 mph.

Overnight will continue to be mild (although not as mild as last
night, with forecast lows expected to remain in the upper 40s to low
50s east of the I-25 corridor, and locations dipping down into the
low to mid 40s further west. For some context, the climatological
overnight low at Laramie tomorrow is 31F, with Cheyenne typically
experiencing temperatures in the mid to upper 30s. A weak surface
front looks to push across SE Wyoming and W Nebraska sometime
tomorrow morning, which will result in a *slightly* cooler day
tomorrow (though still 10-15 degrees above average).

Behind the back door front, a weak inverted ridge will shift the
surface flow to more SSE throughout the day, helping usher in some
slightly richer moisture (dewpoints in the mid to upper 30s) east of
the Laramie Range. In the "cooler" post-frontal air mass, expect
high temperatures to remain in the upper 70s to low 80s. So while
slightly cooler than these past couple of days, it still won`t feel
anything like October outside. Minimum RH values are expected to
range from 15-25%, however fire concerns are low thanks to weak SE
winds of 5-10 knots. With slightly higher low-level moisture behind
the front, cannot rule out an additional round of isolated, high-
based, gusty showers later in the afternoon, confined primarily to
the higher terrain. Expect another mild night on Wednesday into
Thursday as we remain under the longwave ridge pattern, with 500 mb
heights anomalies of +2-3 sigma relative to climatology based off
NAEFS guidance.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
Issued at 1205 PM MDT Tue Oct 6 2026

The long term forecast will change from having warm light winds and
clearer skies to a more active pattern. Starting sometime Friday
night and through the weekend a low pressure system will start to
push in from the Pacific Northwest and begin to start feeding that
Pacific Moisture into the Intermountain West region. THe height
gradient will also begin to tighten so breezier conditions can also
be expected as the process begins to take shape. Depending on which
global model you look at they all paint almost the same overall
picture with some minute timing differences. However with weather,
the details and timing are always the deciding factors with how this
unfolds. Right now, some of the global ensembles have precipitation
starting as early as Sunday morning some have it starting as early
as Sunday night. Which could mean the difference of rain or snow for
our mountain peaks and an earlier snowpack the better in my opinion.
However, everywhere else in our area thats not the peaks of the
Snowy range or Sierra Madres look to be getting rain and high
temperatures look to only drop into the 50`s and 60`s during this
period.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1205 PM MDT Tue Oct 6 2026

It looks to be light winds and relatively clear skies for
terminals through the TAF period. The afternoon wind gusts look
really spotty across our forecast area but even then Winds above
20 knots aren`t really expected. Overnight winds look to go
light and variable with the winds predominately being easterly
from 00z to 06z in the Panhandle. Some high based clouds are
expected to move across the southern terminals but they are
expected to be above 18,000ft for the most part so no impacts to
general aviation are expected.

&&

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

&&

$$

SHORT TERM...NB
LONG TERM...MM
AVIATION...MM