Chadron, Nebraska 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

210
FXUS65 KCYS 220800
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
200 AM MDT Sat Aug 22 2026

.KEY MESSAGES...

- Scattered to numerous showers and thunderstorms expected this
  weekend, with the possibility of widespread rain on Saturday.
  A few strong to marginally severe thunderstorms possible
  Saturday afternoon.

- Daily shower and thunderstorm chances continue Monday through
  the end of the week with slightly above average temperature
  expected until Thursday.

&&

.SHORT TERM /THROUGH SUNDAY NIGHT/...
Issued at 158 AM MDT Sat Aug 22 2026

Not many changes made to the previous forecast with a relatively
wet and warm pattern expected to continue through the last full
week of August. Current surface observations across the region
show ample low to midlevel moisture with dewpoints remaining in
the upper 50s and mid 60s across the eastern plains. A drier
airmass is located over central and south central Wyoming, with
dewpoints in the 30s and 40s. Expect this to change today as IR
and Watervapor Satellite loop shows the next monsoon moisture
plume lifting northeast out of Utah and Nevada at this hour and
into Wyoming later this morning. This plume, in addition to a
potent upper level shortwave, is forecast to drift eastward
around the periphery of the upper level high to our south. This
will also flatten the upper level ridge axis currently over the
Front Range and result in slightly cooler temperatures. NAEFS
still show PWATs between 1.00 (west of I-25) to 1.50 (east)
across the region, and may have trended a bit higher compared to
yesterday with values approaching a two week maximum between
18z and 00z for late August and early September. Getting some
signals for excessive rainfall, especially if any outflow
boundary interactions are considered. Kept POP above 40% for
most of the area with scattered to numerous coverage of showers
and thunderstorms. Not a lot of shear, however, so severe
thunderstorms aren`t as likely. There is a marginal risk for
Severe thunderstorms across the eastern plains of southeast
Wyoming and the southwest Nebraska panhandle...mainly for gusty
winds. Can`t rule out some marginally large hail, but
thunderstorms will likely be linear lines and multicell clusters
with straight hodographs through the afternoon and occasional
periods of weaker shear ahead of the upper level disturbance.
Could see some respectable rainfall amounts with short range
ensembles showing a good chance of a half inch of rain,
particularly along the I-80 corridor, and along/north of highway
20 over east central Wyoming and the northern Nebraska
panhandle as the shortwave axis moves east through the region
later this evening. Cooler today with highs in the 80s under
partly to mostly cloudy skies.

For Sunday, models show some drier air attempting to move into the
forecast area through the day due to increasing west to northwest
winds behind Saturday`s shortwave disturbance. Surface winds
are expected to increase a bit out of the west with gusts of 25
to 35 MPH possible, especially across southeast Wyoming. With
drier conditions and a lack of forcing, expect shower and
thunderstorm coverage to be lower into the evening hours with
widely scattered coverage, mainly further south along the I-80
corridor. 0-6km shear is a little more favorable for organized
convection though, especially over the southern Nebraska
Panhandle. Kept POP between 20 to 35 percent near the Colorado
border with POP around 15 percent north of I-80.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
Issued at 131 PM MDT Fri Aug 21 2026

Monday...Coverage of afternoon and evening showers and thunderstorms
increases somewhat by an increase in monsoonal moisture and lowering
700 mb temperatures providing less convective inhibition, CIN,
compared to Sunday. As is this type of pattern, afternoon convection
will be over and near the mountains due to differential heating and
orographic effects, with the activity spreading across the rest of
the forecast area before dissipation by late evening. Warmer
temperatures compared to the previous day due to less cloud cover
and convective coverage.

Tuesday...Similar pattern synoptically to Monday with minor
perturbations in the flow aloft aiding in lift of monsoonal moisture
to produce widely scattered to scattered afternoon convection over
and near our Snowy, Sierra Madre and northern Laramie Ranges, with
the activity spreading eastward across the rest of the forecast area
in the evening. Some lowering of mid level temperatures suggests
daytime maximum temperatures will be a little cooler.

Wednesday...The primary change compared to Tuesday, will be a
reinforcement of the ridge aloft axis over Wyoming, inducing a
return to upslope mechanical lift aiding the areal increase of
showers and thunderstorms, especially east of the mountains and
along the I-25 corridor and eastward. Slight warming trend with 700
mb temperatures near 13 Celsius yielding high temperatures in the
80s.

Thursday-Friday...Monsoonal moisture becomes a bit more scant with
decent westerly flow aloft and with warm temperatures aloft
producing more convective inhibition, CIN, to limit development. A
slight warming trend continues based on mid level, 700 mb
temperature trends.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1122 PM MDT Fri Aug 21 2026

A relatively calm night is in store with the possibility of
lower VIS and CIGs across the Nebraska Panhandle with the
additional moisture from Friday`s precipitation and wind
direction. Then, winds ramp up once again across all terminals
by 00Z Sunday with southeasterly to southerly gusts 20 to 25
knots. Another round of showers and thunderstorms look to impact
all sites except KRWL starting around 23Z Saturday, therefore
PROB30 groups have been added. Look for lower VIS along with
gusty and erratic winds in any storm activity if it comes near
or over a terminal. Chances persist towards the tail end of this
forecast period.

&&

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

&&

$$

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