Chadron, Nebraska 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

268
FXUS65 KCYS 262320
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
520 PM MDT Wed Aug 26 2026

.KEY MESSAGES...

- There is a Slight Risk (Level 2 of 5) from Laramie county to
  Kimball county. A Marginal Risk of Excessive Rainfall is also
  in place for today.

- There is a Marginal Risk (Level 1 of 5) for severe weather
  for portions of southeast Wyoming and western Nebraska on
  Thursday. Large hail and damaging wind are the primary
  hazards.

- Friday will act as a transition day between active weather to
  more organized active weather Saturday onwards.

- Daily shower and thunderstorm chances expected Saturday
  through at least Thursday, with the potential for strong
  thunderstorms Sunday afternoon.

&&

.SHORT TERM /THROUGH THURSDAY NIGHT/...
Issued at 200 PM MDT Wed Aug 26 2026

The main shows looks to start around 5pm according to model
soundings. Right now we have showers developing off the mountains as
we reach convective temperature. Model soundings had the convective
temp around 75 degrees and its now 78 degrees here at the office and
showers are cropping up along the mountains. The RAP had peak MUCAPE
values at around 2,000 to 2,500 joules by 21-23z in the southern
Panhandle and Laramie county. For our northern counties the
soundings estimated between 600 to 1500 joules with the higher
energy values being over the Panhandle where there is more moisture.
Bulk shear was around 40-50kts looking at the GFS and soundings
pinned around 20-25kts for effective shear. The environment looks a
lot better today for producing severe thunderstorms then it did
yesterday. However, the Lapse rates are not to spectacular ranging
between 7.0 to 7.5C so the storms may take a hot second to develop
their own suitable environment to really intensify into a self-
sustaining storm. SPC has placed a slight risk (level 2 out of 5)
over Laramie county and extended it into Kimball county where the
best environmental conditions lie to produce supercells.

Another active day is anticipated for Thursday as the upper-level
ridge remains in place across much of the Intermountain West. The
ridge is expected to amplify Thursday afternoon with northwesterly
flow aloft continuing. As the ridge amplifies around 21Z Thursday, a
weak jet develops from eastern Montana southeastward into western
and central South Dakota. This positioning will broadly place the
region in the right entrance region of the jet, but it will be much
weaker than what is expected today. The ridge will be pushed back to
the southeast throughout the overnight hours as an upper-level
trough starts to push into the Pacific Northwest by 06Z Friday.
Looking down at 500mb, a similar pattern to Wednesday will setup
with the high over the Four Corners region funneling moisture into
the region and allowing multiple lobes of 500mb vorticity to advect
around the high into the CWA. 700mb flow will be quite weak once
again Thursday afternoon with broad ridging expected to remain
overhead. One big difference between today and Thursday will be the
significantly stronger 700mb WAA on Thursday. A stout surface low
pressure system is projected to develop and move across northeast
Wyoming, favoring increased southerly to southeasterly flow across
the region and stronger surface winds due to the increased pressure
gradient. This low will move eastward, dragging a weak cold front
across the region between 03 and 09Z Thursday night into Friday
morning. Forecast soundings from the HRRR and RAP suggest much more
instability present Thursday afternoon in western Nebraska, with
MLCAPE around 2000 to 2500 J/kg, though 2500 J/kg may be a touch
high. SBCAPE skyrockets to around 2000 J/kg and DCAPE increases to
1300 to 1500 J/kg Thursday afternoon. An isolated storm or two could
become strong to severe Thursday afternoon with the Storm Prediction
Center placing western Nebraska in a Marginal Risk (Level 1 of 5)
for severe weather with damaging winds and large hail as the primary
hazards. Tornadoes, once again, do not look likely. The Marginal
Risk for excessive rainfall is pushed much more to the southeast for
Thursday, only including Kimball to Sidney and points southeastward.
Flooding does not look overly likely Thursday, but heavy rain may
still be possible with Precipitable Water values once again around
an inch in the Panhandle.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Issued at 200 PM MDT Wed Aug 26 2026

Friday starts off this long term period with the upper level ridge
staying put and the trough moving to the east, tilting toward the
northeast. A westerly flow comes to the 700mb height as the ridge
begins to weaken and push out of the area. 700mb winds increase with
the height gradient tightening. Surface winds are expected to be
stronger and gusty. Carbon county can expect to see the strongest
and gustiest winds. Temperatures at 700mb increase between 15 to 19C
in the afternoon on Friday. Afternoon minimum humidity values are
expected to be between 15 to 20 percent for much of the CWA. This
along with gusty winds brings elevated fire weather conditions.

An upper level trough moves through the PNW through this long term
period. Upper level flow increases as the weekend progresses,
supporting chances for showers and storms on Saturday and Sunday.
Sunday looks to be an active day with a trough starting to
negatively tilt over central Montana. A strong jet develops
stretching from eastern Montana through Western Nebraska. Sunday
afternoon will have strong forcing due to much of the region being
in the right entrance region of the upper level jet. Some models
show good WAA at 700mb. This coupled with the strong upper level jet
primes the atmosphere for strong storms on Sunday. More to come as
we get closer to Sunday. Monday and Tuesday bring more chances for
storms and showers. Temperatures stay warm through Saturday then
cool off starting on Sunday, bringing more seasonable temperatures
as we head into September.

&&

.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 520 PM MDT Wed Aug 26 2026

Showers and thunderstorms are pushing through and will affect all
terminals at varying times and to different degrees, except
KRWL and KLAR where they have the best shot at escaping any
impacts. This activity may drop CIGs and VIS for a short period
of time if the storm passes over a terminal. Look for AMDs if
this is the case over the next several hours. Also, anticipate
gusty and erratic winds in any storm activity. After all these
storms push through, a return of VFR conditions are expected
overnight across all the sites with winds generally 10 knots or
less.

&&

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

&&

$$

SHORT TERM...MM
LONG TERM...ML
AVIATION...RZ