Chadron, Nebraska 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

697
FXUS65 KCYS 261103
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
503 AM MDT Wed Aug 26 2026

.KEY MESSAGES...

- There is a Marginal Risk (Level 1 of 5) for severe weather
  Wednesday with a small sliver of a Slight Risk (Level 2 of 5)
  from Cheyenne east to Cheyenne. A Marginal Risk of Excessive
  Rainfall is also in place for Wednesday.

- 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 238 AM MDT Wed Aug 26 2026

Messy, upper-level ridging will continue today as it remains parked
across much of the Intermountain West. Westerly flow aloft turns
northwesterly through the mid-morning hours. A weak jet develops
around 00Z this evening, placing portions of the region broadly in
the right entrance region, favoring synoptic lift across much of the
CWA. Several lobes of 500mb vorticity will advect around the 500mb
high sitting over the Four Corners region and push into southeast
Wyoming and western Nebraska by the afternoon hour. These lobes will
promote some upper-level forcing across the region as the strongest
lobes move through between 21 and 03Z. 700mb flow remains benign
with widespread ridging across the western CONUS. Weak 700mb warm
air advection is expected between 18 and 06Z this afternoon and
evening, leading to weak, lower-level, forcing for ascent. Surface
flow will turn southerly to southeasterly through the mid-morning
hours, advecting in additional moisture throughout the morning and
afternoon hours and providing ascent along the Laramie Range.
Showers and thunderstorms are expected to develop between 12pm and
2pm this afternoon, with the potential for an additional push of
convection around 00Z when the right entrance region of the upper-
level jet moves in. Forecast soundings from the RAP and HRRR suggest
around 1500 J/kg of MLCAPE this afternoon and around 2000 J/kg of
SBCAPE, along with 30 to 35kts of bulk shear by 3PM. A large portion
of the CAPE is present below 0C, increasing the potential for large
hail with storms that form this afternoon. DCAPE values remain
around 1000 J/kg, favoring increased chances for damaging winds as
well. With fairly weak flow throughout the atmosphere, storms motion
will be slow this afternoon and forecast soundings suggest
Precipitable Water values around an inch with the NAEFS Mean
Precipitable Water in the 90th percentile for this time of year. All
of this combined with surface temperatures expected to be in the low
to upper-80s and dewpoints in the 50s, a favorable environment will
be present for strong to severe storms this afternoon. The Storm
Prediction Center has highlighted much of the CWA along and east of
the Laramie Range in a Marginal Risk (Level 1 of 5) for severe
weather, with Cheyenne to Kimball in a Slight Risk (Level 2 of 5)
for severe weather. The Weather Prediction Center has also
highlighted the region in a Marginal Risk for excessive rainfall
this afternoon. Therefore, primary concerns with showers and storms
this afternoon will be damaging wind gusts, large hail, and heavy
rain, potentially leading to localized flash flooding. Luckily,
tornadoes do not look overly likely today.

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 on Wednesday. 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. A diffuse 70mb shortwave looks to push into southeast
Wyoming between 06 and 12Z Friday, likely initiating more convection
or helping sustain any ongoing convection. One big difference
between Wednesday and Thursday will be the significantly stronger
700mb WAA on Thursday, with much of the region east of the Laramie
Range seeing modest to strong WAA. A stout surface low pressure
system starts to develop between 00 and 03 Friday 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. Stronger 700mb WAA in the afternoon will lead to warmer
surface temperatures, in the mid-80s to low-90s across much of the
area. Dewpoints will increase into the 50s once more, providing a
favorable environment for showers and storms along a line of
Cheyenne to Wheatland to Douglas then east into western Nebraska.
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. Bulk shear will also be just a
bit higher between about 35 and 40 kts in the Panhandle. The biggest
question with this setup will be how much the building ridge aloft
mitigates any rising motion under the subsequent sinking motion
expected under a ridge. Currently, 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 TUESDAY/...
Issued at 238 AM MDT Wed Aug 26 2026

A brief reprieve from scattered thunderstorms is anticipated Friday
as the upper-level start to transitioning to another active pattern.
The upper-level ridge remains in place Friday, though starts to move
off to the east and tilt towards the northeast Friday night into
early Saturday morning. The 500mb high over the Four Corners
continues to spin through the afternoon hours Friday, but gets
pushed off to the south and east Friday night into early Saturday
morning. 700mb flow turns more westerly Friday, as the ridge starts
to weaken and move out of the region. A brief period of increased
height gradients at 700mb will promote slightly stronger 700mb
winds, with GFS Omega field suggesting modest downward motion along
and east of the Laramie Range Friday morning through mid-day. Much
as is expected for Wyoming during the year, the slightly stronger
700mb flow and increased downward omega values will lead to stronger
surface winds, especially across Carbon County where strong
southwesterly flow is anticipated to develop. ALl areas have less
than a 30% chance at high winds during this period, but gusty winds
look quite likely. 700mb temperatures also increase for Friday as
the apex of the trough moves directly overhead then off to the east.
700mb temperatures will warm into the 15 to 19C range Friday
afternoon. Surface temperatures look to max out in the upper-80s to
upper-90s in all locations east of the Laramie Range. These very
warm temperatures combined with gusty downsloping winds along and
east of the Laramie Range, as well as minimal precipitation chances,
will lead to elevated fire weather conditions as afternoon minimum
humidity values drop into the 15 to 20 percent range across much of
the area. Red Flag conditions are not anticipated at this time, but
very dry and windy conditions are expected for the afternoon hours.

Saturday onwards will be dominated by the upper-level trough moving
into the Pacific Northwest Friday through the weekend. Active
weather looks to continue Saturday onwards with the much more
progressive upper-level flow. Daily, scattered to numerous showers
and storms are expected Saturday and Sunday afternoons as the upper-
level trough pushes into the region, increasing synoptic forcing.
Sunday looks particularly interesting as the upper-level trough
starts to become negatively tilted over central Montana and a strong
jet develops from eastern Montana southeastward through western
Nebraska. Much of the region will be in the right entrance region of
the strong, upper-level jet, favoring much stronger forcing across
the region Sunday afternoon. While this setup is still several days
out, long range models suggest decent 700mb WAA across the region
Sunday afternoon. When combined with the strong, upper-level jet,
storms could become quite strong Sunday afternoon. Details for this
setup will become clearer over the coming days. Active weather will
continue through the end of the long term period with daily shower
and thunderstorms chances across the region. Surface temperatures
will be quite warm Saturday before cooling off Sunday. More
seasonable temperatures expected Monday through the end of the long
term forecast period.

&&

.AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 503 AM MDT Wed Aug 26 2026

Partly cloudy skies expected across much of southeast Wyoming and
western Nebraska this morning as showers and storms continue to move
off to the southeast. Light winds continue this morning before
increasing in late-morning hours for most terminals. Isolated to
scattered showers and thunderstorms move in the afternoon and
evening, some of which may be strong to severe. Gusty, erratic winds
are possible in and around every shower and thunderstorm that forms
this evening. The strongest storms may have 2+ inch hail and
damaging winds (50+ kts). Winds decrease with clearing skies late
this evening into the overnight hours.

&&

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

&&

$$

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