Chadron, Nebraska 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

091
FXUS65 KCYS 272058
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
258 PM MDT Tue Oct 27 2026

.KEY MESSAGES...

- Drier, warmer, and breezy to windy conditions are expected to
  continue through Wednesday. Another round of morning fog is
  possible over portions of the High Plains Wednesday AM.

- Chances for a few showers return Friday into Saturday
  (Halloween) with temperatures remaining mild.

- A pattern change to colder, wetter, and windier conditions is
  favored Sunday into Tuesday, but the details remain highly
  uncertain at this time.

&&

.SHORT TERM /THROUGH THURSDAY NIGHT/...
Issued at 148 PM MDT Tue Oct 27 2026

It`s still a bit breezy this afternoon as the 700mb jet slowly
begins to calm down. While high winds aren`t expected this afternoon
wind gusts between 45 and 55 mph can still be anticipated on I-80
between Rawlins and Laramie as well as I-25 in between Casper and
Douglas. As the system continues to lift back into the Canadian
Providences we will continue to see the 700mb jet weaken and the
upper level ridge begin to take back over. Other than some high
level clouds moving through the area not much should be expected in
the short term forecast. Another weak shortwave is expected to be
passing through the Intermountain west tonight. We will see some
increased cloud cover and stable temperatures overnight around
40 to 45 degrees. But otherwise any precip chances look to be
contained in the Northwestern portion of Wyoming and possibly
Central Wyoming. Under this ridge 700mb temperatures are going
to be around 6C which means high temperatures will be around 60
to 65 for locations east of the I-25 corridor and between 50 and
55 for the higher elevations west of the I-25 corridor.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
Issued at 255 PM MDT Tue Oct 27 2026

On Friday, we will once again see a broad ridge in place over the
Central CONUS. This iteration of this familiar weather pattern will
be less amplified, not supporting warmth as significant as what we
had earlier this month. With troughing inching into the west coast,
southwest flow aloft will continue to prevail. Models are in fairly
good agreement showing low-level south to southeast winds advecting
in improved low-level moisture to the High Plains Friday while
moisture aloft improves with another influx of tropical moisture. By
the end of the day Friday, NAEFS mean precipitable water exceeds the
90th percentile of climatology for much of the area. As has been our
problem frequently as of late, we will not have much forcing for
ascent, despite the abundant moisture. This begins to change Friday
night as two disturbances are pulled out of the southwest. The first
will be associated with the remnant moisture of Tropical Storm
Vance, the latest in the parade of eastern Pacific tropical systems
pushed into the southwest CONUS. This remnant vort-max will track
further east than its predecessors, moving mostly over the Plains.
There is a possibility (about 30% chance) for some showers Friday
night into Saturday, mainly in the Nebraska panhandle. Another more
disorganized vort-max tracking further west will bring potential for
afternoon and evening showers and high elevation snow showers mainly
to the mountains and adjacent zones on Saturday (Halloween). Other
than the potential for a few light showers, expect generally good
trick-or-treat conditions with highs in the mid 50s to mid 60s and
overnight lows dropping only into the upper 30s to mid 40s. Winds
look fairly light as well.

Forecast confidence decreases considerably as we head into the
Sunday through Tuesday time period. While there is still potential
for widespread precipitation, the ensemble spread is enormous as a
very complex weather pattern sets up over the Western CONUS. First,
a powerful disturbance will race into the southwest, riding on a
very strong sub-tropical jet stream. Meanwhile, a northern branch
trough will dive into the northwest and progress eastward
simultaneously. The northern upper level low may also close off from
the polar jet itself, adding to the uncertainty. With so many moving
parts on the board, it is difficult to have much forecast confidence
in how this will play out.

In lieu of that, we can discuss some possible scenarios.
Approximately 45% of LREF members are clustered into a scenario
showing a more progressive storm system. This is further split
between about half of this camp showing a storm that remains
progressive, and half showing a storm that eventually closes off
and strengthens, but this occurs too far east to deliver much
precipitation to our area. In this scenario, most of the area
could expect light precipitation amounts, generally 0.25" or
less. The remaining 55% of ensemble members have a deeper,
stronger system with better forcing for lift, and thus improving
chances for precipitation. About 30% of the full ensemble suite
(a subset of the 55%) have a moderate precipitation event,
where the system is strong and deep, but still progressive. The
final 25% (again a subset of the 55%) depict a slow, strong
upper level low closing off before reaching our area, which
would lead to widespread heavy precipitation for much of the
area, but especially over the High Plains. The ECMWF Extreme
Forecast Index provides some additional context. EFI values for
QPF on Monday are only around 0.5 to 0.7, suggesting low
confidence in a significant event. However, the shift of tails
values exceed 2.0 over much of the High Plains, which tells us
that a small subset of ensemble members depict an extreme event.
Thus, the main takeaway at this time should be that at least
some light precipitation is narrowly favored (60% chance) over
much of the area Sunday PM into Tuesday AM, and there is
potential for significant rain and/or snow, but the probability
of this scenario is fairly low (25% chance) at this time.
Nonetheless, this is high enough to discuss and continue to
monitor closely in the coming days. Most model guidance shows
limited cold air with this system once again, and the wettest
ensemble members also tend to be the warmest (as these close the
low off faster). This will make snow levels an issue once
again. Regardless of the precipitation outcome, expect cooler
temperatures by Monday with blustery conditions. There is
potential for high winds as well, but we`ll wait to get a better
idea of the storm`s evolution before diving into those details.


&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1140 AM MDT Tue Oct 27 2026

This morning`s round of low clouds and fog is almost cleared
out, and will finish doing so in the next hour. Otherwise, look
for wind gusts between 20 and 30 knots in Wyoming and at CDR
this afternoon (possibly 35 knots at RWL). All except RWL should
ease around sunset, though marginal LLWS is possible at LAR and
CDR overnight.

There is high confidence in another round of low clouds and fog
affecting BFF, AIA, and SNY overnight into Wednesday morning.
Expect this to clear out mid to late morning as winds turn
westerly across the area.

&&

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

&&

$$

SHORT TERM...MM
LONG TERM...MN
AVIATION...MN