Chadron, Nebraska 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

609
FXUS65 KCYS 211107
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
507 AM MDT Tue Apr 21 2026

.KEY MESSAGES...

- Elevated to Critical Fire Weather conditions expected again
  Tuesday as humidities dive into the single digit values with
  light winds. A Red Flag Warning remains in effect for all
  areas east of the Laramie Range until Wednesday evening.

- There is a Marginal Risk (Level 1 of 5) for severe weather
  Wednesday afternoon. The primary concerns will be damaging
  winds gusts caused by microbursts.

- The potential for high winds will return Wednesday afternoon
  into Thursday. This may event spread outside of the wind prone
  areas. A High Wind Watch has been issued for Wednesday
  afternoon through Thursday evening.

- A cooler weather pattern with more frequent chances for precipitation
  will take over Thursday and last into early next week.

&&

.SHORT TERM /THROUGH THURSDAY NIGHT/...
Issued at 151 AM MDT Tue Apr 21 2026

Clearing skies tonight as temperatures continue to drop across the
region. Mostly light winds are ongoing as dry air continues to move
in. Dewpoints remains quite low tonight, in the 9 to 20F range,
leading to poor overnight humidity values nearly everywhere as
temperatures remain in the mid-30s to mid-40s. Clear skies will
continue today, with very dry conditions expected to continue this
afternoon and into the overnight hours and Wednesday evening.

Upper-level ridging continues today ahead of an upper-level trough
pushing into the western CONUS this afternoon and evening. The
incoming trough will take a day or so to organize as it slowly
meanders eastward Tuesday evening through Wednesday afternoon. Under
the ridging Tuesday and most of Wednesday, clear skies and warm
temperatures are anticipated as 700mb temperatures warm into the 10
to 15C range, leading to surface highs in the upper-70s to upper-80s
Tuesday and upper-70s to possibly the low-90s for Wednesday.
Precipitation chances remain little to none Tuesday through
Wednesday morning. With very warm temperatures and largely dry
conditions across the CWA, relative humidity values will be
extremely low Tuesday and Wednesday, likely in the 5 to 12 percent
range, especially east of the Laramie Range.

Wednesday afternoon looks to be quite interesting as the upper-level
trough starts to push into the region and multiple 500mb vorticity
lobes eject out ahead of the approaching trough. 700mb flow starts
to switch southwesterly across western portions of the CWA and
westerly across eastern portions of the area as the 700mb system
starts to deepen over northern Idaho and western Montana. 700mb
height gradients begin to increase, leading to a strengthening 700mb
jet to 50 to 55kts across western portions of the area. Surface
winds respond as modest subsidence is expected. Winds will likely
approach high wind criteria by late Wednesday morning into the early
afternoon hours, so a High Wind Watch has been issued for much of
the area west of the Laramie Range from 9AM Wednesday through 6PM
Thursday. Additionally, strong subsidence combines with strong 700mb
flow and increasing surface gradients across the Snowy Range,
suggesting very strong winds at the Arlington/Elk Mountain wind
prone area along I-80. Craig to Casper 850mb gradients increase to
75 to 80m late Wednesday evening into the overnight hours, with a
very strong surface pressure gradients across the zone as well.
Therefore, a High Wind Watch has been issued for this zone for the
same time, with wind gusts up to 75mph possible in this zone. Winds
are expected to expand eastward as a 700mb shortwave develops across
the Laramie Range and a very strong surface pressure gradients
develops with the approaching cold front. A 3 to 4mb gradients is
expected across the Laramie Range, with a 12mb gradient from western
Carbon County eastward to the Laramie Range. Very strong winds are
anticipated at Bordeaux, the I-80 Summit, Central Laramie County,
and Converse County. Therefore, High Wind Watches are in effect for
these areas as well, with Bordeaux and the I-80 Summit expected to
gust upwards of 80mph. As strong winds kick up to the west of the
Laramie Range, east of the Laramie Range will see increasing lift as
vorticity maxima push overhead and cold front pushes towards the
area, leading to increasing shower chances. However, very dry
surface conditions are expected so precipitation will likely
evaporate before hitting the ground. RAP soundings suggest a stout
Inverted-V signature across the Panhandle, with CAPE values around
the 500 J/kg mark. Therefore, isolated showers and storms are
possible, leading to increasing dry lightning concerns with virga
showers across the Panhandle. Red Flag Warnings remain in effect
through Wednesday evening and the Storm Prediction Center has
highlighted eastern portions of the Panhandle in a Marginal Risk
(Level 1 of 5) for severe weather (mainly wind) Wednesday afternoon
and evening. West of the Laramie Range is expected to see mostly
snow as the strong cold front pushes through, leading to snow
accumulations between 3 to 6 inches for the mountains and trace to
half an inch of snow in the lower elevations west of the Laramie
Range.

A secondary surge of winds is expected to develop Thursday morning
as the 700mb low continues to strengthen and moves into western
North Dakota. A very strong 700mb height gradients is expected
across the region, leading to a 700mb jet up to 70kts across the
Laramie Range, namely the I-80 Summit.  Looking at GFS Omega Values,
very strong subsidence is expected west to east across the Laramie
Range and expanding into central Laramie County, especially late
Wednesday night and early Thursday morning. The initial portion of
this High Wind Event looks to be a Bora Event behind the strong cold
front, with a mountain wave likely setting up later on. The
strongest gusts at many locations are expected late Wednesday night
into early Thursday morning, with gusts over 80mph possible near
Bordeaux and the I-80 Summit. Winds finally begin to settle down
Friday evening as the 700mb low continues to move away from the
region. However, a gusty 24+ hour period looks likely for much of
the area. Temperatures on Thursday will be much cooler, in the upper-
40s to mid-60s across the area. With the cooler air moving into the
region, any ongoing showers east of the Laramie Range are expected
to quickly transition over to snow, except for the Panhandle where
warmer temperatures are expected and primarily rain to a rain/snow
mix are anticipated. QPF with this system looks fairly low east of
the Laramie Range, so significant precipitation is not expected, but
a few hundredths may fall which is better than none. For additional
information, please see the modified long term discussion below.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
Issued at 151 AM MDT Tue Apr 21 2026

No major changes with the forecast update. Please see the previous,
modified long term discussion...

A secondary vort-max will rotate around the longwave trough,
arriving Thursday afternoon into Friday. This will knock down
temperatures further, with highs expected to be about 5 to 10F below
seasonal averages for Friday. In addition, the upper level
disturbance will bring increased chances for widespread light
precipitation. While some light snow and/or rain is probable with
PoPs in the 40 to 60% range, LREF probabilities for 0.10" or more of
liquid precipitation is around 30 to 50% for most of southeast
Wyoming, and 10 to 30% for most of western Nebraska. Concerning
precipitation type, the chilly temperatures will support snow for
the majority of those areas that manage to see precipitation.

Temperatures will remain chilly through the weekend. 700-mb
temperatures will be near the climatological 10th percentile. LREF
means are around -4C, but the interquartile range stretches from
around -7C to -1C, indicating fairly low confidence in exact
temperatures. The chill will be held in place by a broad, and
unseasonably strong  upper level low over the Canadian prairie,
which will also keep the baroclinic zone over our area. Thus, expect
the weather pattern to remain unsettled through this period. Another
upper level low will move in across the western US and across the
Four Corners states late Saturday into early Monday. This will take
a more favorable track for widespread precipitation across our area.
In addition, models are in fairly good agreement showing a surface
high settling in over the northern Plains, allowing for an
improvement in surface dewpoints and surface winds generally out of
the south to east direction. For this system, LREF probabilities for
0.1" of precipitation or more are around 50 to 70% for the entire
area. This drops down to 20 to 40% chance for greater than 0.25",
and a 10 to 20% for greater than 0.5". Precipitation type will be a
little more complicated with this event with the large spread in 700-
mb temperature shown by various ensemble members. The warmer end
would be rain for most areas outside of the mountains, while the
colder end would be snow for almost everyone. The NBM may be a
little on the cold side for snow levels for this event, but overall
the most likely scenario is a rain/snow mix. High temperatures will
be 10 to 20F below average through the weekend, with lows around 5
to 10F below average due to the increased cloud cover. The positive
news of the cooler weather pattern is that we can expect a break
from the fire weather concerns for several days, even if the
precipitation fails to materialize.

&&

.AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 506 AM MDT Tue Apr 21 2026

Mostly clear skies expected through much of the 12Z TAF period.
Clouds will slowly increase west to east late in the period. Gusty
winds are expected to return this afternoon, with gusts between 20
and 25kts for most terminals. Lighter winds return this evening.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...Red Flag Warning from 11 AM this morning to 8 PM MDT Wednesday
     for WYZ417-418-430>433.
     High Wind Watch from Wednesday evening through Thursday
     afternoon for WYZ101.
     High Wind Watch from Wednesday morning through Thursday
     afternoon for WYZ104-109-111-113.
     High Wind Watch from Wednesday afternoon through Thursday
     afternoon for WYZ106-116>118.
     High Wind Watch from Wednesday morning through Thursday
     afternoon for WYZ110.
NE...Red Flag Warning from 11 AM this morning to 8 PM MDT Wednesday
     for NEZ434>437.

&&

$$

SHORT TERM...AM
LONG TERM...MN/AM
AVIATION...AM