Chadron, Nebraska 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

219
FXUS65 KCYS 251742
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
1142 AM MDT Tue Aug 25 2026

.KEY MESSAGES...

- Near average temperatures through Wednesday, with a slight warming
trend late this week and into the weekend.

- A few thunderstorms Tuesday and Wednesday may produce strong gusty
winds, marginally large hail, and very heavy rainfall.

- Daily precipitation chances expected Friday onwards.

- Strong winds possible Friday and Saturday, but high winds are not
anticipated at this time.

&&

.SHORT TERM /THROUGH WEDNESDAY NIGHT/...
Issued at 200 AM MDT Tue Aug 25 2026

Yesterday`s thunderstorm activity still lingering across the
northern and central Nebraska Panhandle at this hour as a line of
strong thunderstorms pushed across the eastern high plains late last
night, produce widespread wind gusts of 45 to 55 MPH.
Current KCYS radar loop shows this line of storms weakening and
pushing into central Nebraska this hour with a few trailing rain
showers. Surface analysis shows the surface cold front has moved
south into the I-80 corridor and the Colorado border, likely aided
by the outflow from the line of thunderstorms to the north.
Expect this front to stall and be the focus for convection
initiation Tuesday afternoon.

Models continue to show the next potent shortwave trough, embedded
in northwest flow aloft, digging southeast across the I-25 corridor
and the eastern plains this afternoon. 0-6km shear has ticked up a
bit compared to yesterday, with MLCAPE around 600 to 1200
j/kg...locally higher (near 2000 j/kg) over the southern panhandle
based on model soundings. Environment not as favor further north
away from the stalled front, with a more stable boundary layer and
lower CAPE. Thankfully, the lowest 0-6 km shear is colocated with
the highest CAPE, so not expecting a super active day. However, a
few thunderstorms will likely become severe or marginally severe
with strong gusty winds, large hail, and very heavy rainfall. A
Marginal Risk for excessive rain continues today (and Wednesday)
along the I-80 corridor and as far north as the North Platte River
Valley. Continued to increase POP between 40 to 60 percent for
scattered/numerous showers and scattered thunderstorms. Will have to
watch the position of the front, since this is where thunderstorms
may train over the same area.

Similar conditions on Wednesday as another transitory shortwave
moves southeast across the same area. Higher boundary layer moisture
as well with PWATS approaching the 95th percentile. However, models
are showing a bit more CIN below 700mb as the front lifts north as a
warm front and stalls. High resolution models are showing a limited
coverage of showers and thunderstorms due to low clouds and maybe
some fog in the morning. Will have to keep an eye on this trend
since Wednesday was looking like the best potential for excessive
rainfall and some flooding. Kept POP as is but did lower them
slightly further east into western Nebraska. Convective variables
look good, with the exception of the low stratus seen on model
soundings. Believe high res guidance is underplaying the potential,
since good surface convergence is expected with easterly winds east
of the Mountains, and a continuation of west to northwest winds
across Carbon and Albany counties. Will also need to keep an eye on
severe thunderstorms since 0-6km shear will be higher with models
indicating MLCAPE of 1000 to 2000 j/kg across the eastern plains.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
Issued at 159 AM MDT Tue Aug 25 2026

Upper-level ridging will continue to dominate the early portion of
the long term forecast period until it starts to breakdown Friday
into Saturday. This ridge will start to intensify on Thursday with
northwesterly flow moving in aloft. With northwesterly flow also
anticipated at 500mb, multiple vorticity maxima will move around the
500mb high over the Four Corners and push across the region from the
northwest. This will induce some forcing for ascent across the CWA.
The 700mb flow will be messy at best on Thursday with ridging to
start the day before a shortwave pushes through and turns winds out
of the south and southeast for locations east of the Laramie Range.
Modest 700mb warm air advection will be possible as the shortwave
pushes into the CWA, with the strongest WAA possible in and around
the South Laramie Range from Laramie to Cheyenne. 700mb temperatures
will warm into the 13 to 15C range Thursday afternoon, with
southeasterly winds east of the Laramie Range favoring upslope
development of the South Laramie Range. Despite warming 700mb
temperatures, surface temperatures are anticipated to remain in the
low-80s to low-90s Thursday afternoon, with moisture starting to
funnel in from the south due to the southerly flow. GFS soundings
suggest modest CAPE possible, though potentially capped, in the
afternoons, around 1000 J/kg. Soundings also suggest decent turning
with height, and around 35 to 40 kts of 0-6km shear. This would be
enough to get a few isolated strong storms, if they can overcome the
cap.

A similar setup is expected for Friday as the upper-level ridge
remains overhead, but starts to flatten out Friday night into
Saturday morning. Westerly flow is expected at 500mb as the ridge
weakens with the peak starting to flatten out. A few lobes of 500mb
vorticity look to advect through the 500mb flow and into the region,
though the strength looks much weaker than the lobes passing through
on Thursday, but the overall coverage increases a touch. Therefore,
more widespread, weak, synoptic forcing for ascent should develop
across much of the region Friday afternoon. Westerly 700mb flow is
also expected as the shortwave moves across the region ahead of the
next incoming shortwave expected for Saturday. 700mb height
gradients will increase, leading to a stronger, westerly jet around
35kts by Friday evening. WAA will increase Friday evening as
downsloping along the Laramie Range increases with the 700mb jet
overhead. Surface temperatures on Friday are anticipated to be hot
once more, with highs in the mid-80s to upper-90s across much of the
area. Despite synoptic forcing for ascent and increasing 700mb
temperatures, precipitation will be hard to get, largely due to
downslope drying off the Laramie Range and out into the Plains. Kept
low PoPs due to some uncertainty in exactly how much precipitation
will be possible, but organized convection appears unlikely at this
time.

Saturday onwards becomes much more active across the region as an
upper-level trough starts to dig south out of Canada into Montana
and North Dakota. Strong, southwesterly flow will develop between
the trough to the north and the ridge to the south, placing the CWA
in a region of strong, southwesterly flow aloft. The 500mb high over
the Four Corners Region will push southeastward as the ridge begins
to interact with the incoming trough, leading to west-southwesterly
flow at 500mb Saturday through the start of the week. Multiple lobes
of 500mb vorticity will push through daily across the region,
favoring increased precipitation chances throughout the weekend into
the early half of the work week. Looking down at 700mb, a shortwave
is progged to push through the region Saturday. 700mb height
gradients increase and result in a jet around 40kts through the
early morning into the midday timeframe. A surface low develops
Saturday morning and pushes off to the northeast, increasing surface
pressure gradients across the region. GFS downward omega values
along the Laramie Range will be quite high, leading to increased
concern for strong, downsloping winds Saturday morning. High Winds
are not anticipated at this time, but the setup looks favorable and
will continue to be monitored. The remainder of the long term will
see daily precipitation chances and seasonable temperatures across
the region.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1140 AM MDT Tue Aug 25 2026

A surface cold front will push south over Wyoming and into the
eastern high plains today. More storms and showers are expected to
develop this afternoon over far southeastern WY and push into the
eastern plains this evening. VFR conditions are expected to prevail
through this TAF period. All terminals except KRWL and KCDR have the
PROB30 group with this storm coverage. Locally heavy rainfall and
strong winds with gusts up to 50 knots are possible, resulting in
brief IFR conditions.

&&

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

&&

$$

SHORT TERM...
LONG TERM...AM
AVIATION...ML