Chadron, Nebraska 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

828
FXUS65 KCYS 201120
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
520 AM MDT Mon Apr 20 2026

.KEY MESSAGES...

- Critical Fire Weather conditions expected again Monday as
  humidities dive into the single digit values.

- Pattern change alongside a chance at some precipitation
  including storms and snow expected mid through end-week
  timeframe.

&&

.SHORT TERM /THROUGH TUESDAY NIGHT/...
Issued at 244 AM MDT Mon Apr 20 2026

Benign weather is expected over the next few days as upper-level
ridging moves into the Rockies. Temperatures will continue warming
on both Monday and Tuesday as the ridge axis pushes eastward
into the CWA. 700 mb temperatures will climb to about +8C on
Monday, leading to high temperatures in the 70s and 80s across
the forecast area. Highs are expected to be even warmer on
Tuesday as the ridge axis sits over the CWA. 700 mb temperatures
will reach +10C, leading to highs in the 70s to upper 80s,
which is roughly 20 degrees above average and approaching record
highs. The ridge will also ensure that mostly sunny skies
dominate the area, with minimal precipitation chances
anticipated. As a result, conditions over the next few days are
expected to extremely dry. With dry desert air being advected
into the region, relative humidity values will fall into the
single digits on both days. The extremely low relative humidity
poses fire weather concerns, especially on Monday when winds are
bit more breezy as a weak disturbance passes to the north. Red
Flag Warnings are currently in effect through Monday for areas
east of the Laramie Range. Overnight humidity recoveries are
also expected to be poor Monday nights. Although precipitation
chances are expected to be minimal, cannot rule out some gusty
virga showers late Tuesday afternoon and evening. Hi-Res
guidance does show some weak convection developing over
southeast Wyoming ahead of a major incoming trough. Model
soundings show strong inverted-V profiles meaning extremely dry
low-levels. Over 1000 J/kg of DCAPE is also likely, leading to
the potential for severe wind gusts in these virga showers.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Issued at 255 PM MDT Sun Apr 19 2026

The main stories on Wednesday are likely to be the high winds and
low RH values for Wyoming, and severe thunderstorm potential for
the Nebraska Panhandle. The upper level system over the Pacific
Northwest will shove the ridge we`ve been dealing with for the last
few days out to the east. Within the southwesterly flow we can
expect increasing cloud coverage, starting first west and spreading
east. While the ridge begins departing our area, it will still
influence our temperatures and humidity. Temperatures are likely to
reach the mid 70s to mid 80s over the High Plains and mid 60s over
the interior basins. Ensemble models are still split on how deep the
upper level low will be Wednesday. Euro and Canadian ensemble
members are leaning towards a weaker system. GEFS members are
deeper. This may have some implications on the magnitude of our
winds and precip probabilities. For example the deterministic model
runs of the ECMWF and GFS have differing central pressures, of the
expected developing surface cyclone to our north, of 991 mb and 987
mb respectively. The surface wind fields of the differing strength
systems are readily apparent with more widespread and stronger winds
in the GFS solution. This is important to take into consideration
when talking about our ML models that predict wind probabilities as
these do take GFS grids as input. This model is predicting high wind
criteria being met at many of our wind prone locations. The
Arlington area has a 80% chance of reaching high wind criteria,
Cheyenne 55%, and Bordeaux a 85%, just to list a few outputs. Local
knowledge tends to favor the GFS as having a better handle on winds
for the area. It should not surprise anyone if high wind products
are issued should the stronger solutions look to verify. Adjusting
our attention east to the Nebraska Panhandle, in the afternoon a
dryline will take shape and be associated with the development of
the low to our north. ML severe weather models are running more
aggressive compared to yesterday in their probabilities of severe
thunderstorm development along this dryline and points east of the
CWA. GFS soundings are depicting a deep mixing layer and inverted-v
profile that may support severe wind gusts. The bulk wind shear is
just enough to possibly support rotating updrafts and increase the
hail potential. How far west this dryline ultimately positions
itself and where it mixes east during the afternoon and evening will
determine if storms mature within our area. The storm coverage looks
to be low at this time. Finally lets talk about the fire potential
as this does seem to be the biggest concern for Wednesday. As
mentioned, high winds are of higher confidence and relative humidity
values are likely to bottom out in the low teens across the majority
of the CWA. Therefore red flag conditions are plausible.
Additionally, with the introduction of thunderstorms in the Nebraska
Panhandle, dry lightning and variable surface winds induced by
nearby downdrafts can further complicate any fire behavior.

Winds increase overnight Wednesday as the surface low departs to the
northeast. Aloft we are still at the base of an upper level trough,
which should increase PoPs, particularly over the mountains and
northern poritons of the CWA. A Pacific cold front should move in
from the west and brings our temperatures down slightly and increase
moisture a little. Precip accumulations are expected to remain low.
Some remaining elevated fire weather conditions may persist during
the afternoon in the plains region as humidity values stay in the
20s.

Going into the overnight hours Thursday precip chances continue to
increase, particularly over the mountains. An arctic cold front
should make its way through our area sometime around midnight. This
front should finally bring temperatures to near average Friday.
Humidities during the day still appear to be on the lower side.
Regardless, weaker winds and lower temperatures are likely to dampen
fire potential. Saturday and Sunday look to be much the same as
Friday weather wise. There is a good chance the base of the trough
remains parked above the area all weekend, keeping it seasonable
cool, cloudy, and perhaps showery as well.

&&

.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 520 AM MDT Mon Apr 20 2026

Upper level ridge axis will move east over the Front Range during
the day. Generally clear skies are expected with minimal aviation
impacts. VFR conditions will continue over the area. Typical diurnal
winds expected for all terminals with westerly winds becoming breezy
after 16z Monday.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...Red Flag Warning until 8 PM MDT this evening for WYZ417-418-
     430>433.
NE...Red Flag Warning until 8 PM MDT this evening for NEZ434>437.

&&

$$

SHORT TERM...SF
LONG TERM...RV
AVIATION...SF