Chadron, Nebraska 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

145
FXUS65 KCYS 250529
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
1129 PM MDT Wed Jun 24 2026

.KEY MESSAGES...

- Numerous to widespread showers and thunderstorms are expected
  to begin mid afternoon with multiple rounds possible through
  Thursday evening.

- Very large hail (up to 4 inches in diameter), strong damaging
  winds, and a few tornadoes are possible Wednesday afternoon
  and evening, though the threat is conditional upon storms
  breaking through a robust capping inversion.

- A Flash Flood Watch has been issued for the South Fork burn
  scar area due to the potential for multiple rounds of
  thunderstorms with heavy rainfall in the vicinity.

- Strong winds and heavy rainfall are the primary concerns with
  Thursday`s thunderstorm activity, though large hail is still
  possible

- Warming temperatures, falling humidity, and increasing winds
  will increase fire weather concerns this weekend into early
  next week.

&&

.SHORT TERM /THROUGH THURSDAY NIGHT/...
Issued at 230 PM MDT Wed Jun 24 2026

We have another conditional threat for severe thunderstorms today
across the area. A moisture laden, unstable atmosphere is present
with ample vertical wind shear and strong forcing for ascent as a
shortwave trough approaches the area. However, as yesterday, we have
a stubbornly strong cap in place over most of the High Plains. The
low cloud deck has been very slow to break up this morning
especially across Laramie county and the southern Nebraska
panhandle. Mesoanalysis indicates that MLCIN is still fairly potent
over most of the area, though instability is growing over top.
MLCAPE is already 1000 to 1500 J/kg, and expected to increase up to
about 1500 to 2000 J/kg later this afternoon. Vertical wind shear is
quite substantial. 50 to 60+ knots of deep layer is certainly
sufficient to support strong to severe thunderstorms. That being
said, all of this depends on a storm managing to break through the
robust capping inversion. This failed to occur yesterday, but
synoptic forcing for ascent is a bit stronger today thanks to
stronger overrunning lift and vorticity advection aloft overtop the
stalled frontal boundary. So, overall, we have a fairly conditional
but still substantial severe threat today. If forcing is enough to
get a storm through the cap, it will have the potential to become
quite severe with very large hail, frequent lightning, heavy
rainfall, strong winds, and a few tornadoes possible. Locally,
this looks most likely to happen in Converse, Platte, and
Niobrara counties here in the next few hours.

In addition to the typical severe threats, the very high
moisture content approaching climatological maximums combined
with the potential for multiple rounds of storms will support
the potential for localized flash flooding concerns. Confidence
is not high enough in widespread flash flooding concerns to
issue an area wide Flash Flood Watch. However, it will only take
one storm moving directly over the South Fork burn scar to
cause significant problems there due to the heightened
sensitivity in that area. Thus, a Burn Scar Flash Flood Watch
was issued for the area beginning this afternoon and continuing
through Thursday evening. There is about a 70% chance for
thunderstorms occurring over the burn scar, and perhaps a 50%
chance for this potential storm to be producing rainfall rates
sufficiently high to lead to debris flow.

Strong isentropic ascent continues through the overnight hours with
500 to 1500 J/kg elevated MUCAPE continuing. As a result, most of
the area maintains PoPs through the night and into Thursday morning.
The threat for extremely large hail will decrease after about
midnight, but an isolated embedded storm may still produce strong
winds and/or severe hail. Continued upslope flow in the lower levels
overnight will support the development of another round of morning
fog and low clouds.

Thursday will continue the stormy weather pattern. While
temperatures will be cooler across the area and low clouds will
still be present in the morning, capping looks like less of a
concern on Thursday. This will be due to the decrease in
temperatures around 700-mb anticipated over the next 24 hours, which
will decrease the magnitude of the warm air inversion aloft. On the
flip side, lapse rates and instability look lower weaker tomorrow
compared to today. After a morning to early afternoon round of
showers with embedded thunderstorms, we will need to watch for
another late afternoon and evening round of stronger thunderstorms
organized along surface frontal boundary trailing south of a
shortwave trough passing to our north. It continues to appear likely
that this will help storms organize into a linear feature riding on
the leading edge of a strong surface cold pool. The shallower lapse
rates and linear forcing suggest a decreased hail risk on Thursday,
but perhaps an increased risk for strong thunderstorm winds. High
resolution models struggle to handle this mesoscale cold front upon
reaching the surface high entrenched over the High Plains. Falling
surface pressure over western Wyoming, eastern Idaho, and northern
Utah will increase southerly flow Thursday night, leading to good
moisture return and another round of low clouds or fog into Friday
morning.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Issued at 230 PM MDT Wed Jun 24 2026

Friday...Low amplitude ridging develops over our forecast area, with
some drier air noted advecting in. However, still expect isolated to
widely scattered afternoon and evening thunderstorms to form along a
low level convergence axis along the I-25 corridor. A few strong and
possibly severe storms may occur.

Saturday...The flow aloft turns southwest and increases in speed,
with considerably drier air moving across our counties, producing a
dry day with a warming trend as 700 mb temperatures spike near 16
Celsius.

Sunday through Wednesday...A broad trough aloft develops across the
northern and central Rockies, with dry southwest flow aloft, leading
to only isolated to widely scattered thunderstorms at most in the
afternoons and evenings. A progressive shortwave trough aloft is
progged to move to the western Dakotas on Monday, with its
associated cold front bringing a cooler airmass behind the likely
moisture starved cold front. The dry southwest flow aloft continues
for Tuesday and Wednesday with a slow warming trend.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1129 PM MDT Wed Jun 24 2026

Showers and thunderstorms will continue into the overnight hours,
resulting in VFR and potentially MVFR for terminals that are
directly impacted. Confidence is low (20%) that terminals will
receive a direct hit from any shower or thunderstorm as coverage
has been rather spotty, but any stronger storm may lower CIGs
to below 500 feet. Low-level moisture is also abundant and winds
are anticipated to remain light, under 10 knots into the early
morning hours for the Nebraska terminals. Otherwise, expect
MVFR conditions with stratus lingering throughout the area.
Another round of showers and thunderstorms is expected later
tomorrow afternoon into the evening, with greater confidence
(~40%) in higher coverage relative to today as hi-res models
have been consistent in depicting more linear convection.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...Flash Flood Watch through Thursday evening for NEZ002-095.

&&

$$

SHORT TERM...MN
LONG TERM...RUBIN
AVIATION...NB