Chadron, Nebraska 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

387
FXUS65 KCYS 292013
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
213 PM MDT Wed Jul 29 2026

.KEY MESSAGES...

- Monsoon moisture will remain in place through the end of the
  week across the high plains. Heavy rainfall and localized
  flooding possible through Wednesday night.

- More heat returns this weekend through Monday, with some near
  record high temperatures possible along with drier conditions.

&&

.SHORT TERM /THROUGH FRIDAY NIGHT/...
Issued at 211 PM MDT Wed Jul 29 2026

Scattered to numerous showers are expected this afternoon. Model and
observational soundings show CAPE levels between 1000-1500 joules.
However, the observational sounding from Ft. Collins has the most
unstable Cape closer to the surface while the model soundings had
more of the MLCAPE being the most unstable. DCAPE was also around
1200 joules with a slightly inverted V sounding, so gusty showers
are going to be the highest threat from any storm or shower. Some
small hail also can`t be ruled out as shear is around 16kts. the
weak shear will transform the environment from a stable on to a
pulsy unorganized one. So with these temporary pulse ups, some BB to
pea size hail may develop intermittently while as the storm
collapses or recycles, wind gusts between 55 to 65 mph may occur in
a wet microburst type outcome. Any potential severe thunderstorm
warning that comes from the office today will most likely be from
the "severe" wind threat. Around 00z or 6 PM a stream of vorticity
will enhance the synoptic support for these thunderstorms near the
border of Wyoming and Nebraska. Models consequently show the storm
mode changing from discrete to a more linear storm mode. If the
linear storm mode occurs then the wind threat and heavier rainfall
threat will increase. These showers are likely to last until 10 pm
then the synoptic forcing significantly decreases as the overnight
period progresses.

Thursday into Friday, The central high pressure of this upper level
ridge starts to meander westward back towards the four corners
region. Hi-res models show an isolated to scattered shower risk
Thursday afternoon and evening as a result from another weak
shortwave moving through the Intermountain West. Looking the at
700mb RH parameter, models may be drying out the lower regions a
little more quickly than what is realistic in a monsoonal moisture
environment. However, any severe potential will most likely confined
to any severe wind risk much like today. NAEFS is also capturing the
westward shift of central pressure and forecasting increasing mid-
level temperatures closer to the 90th percentile for Southeast
Wyoming. Daily forecasted high temperatures are slated to slowly
shift back into the 90`s across the forecast area as that warm air
advection increase as well as lower afternoon humidity levels to
prop up the potential for heat advisories and elevated fire weather
concerns for this weekend.


&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
Issued at 211 PM MDT Wed Jul 29 2026

A ridge axis will be firmly in place for our Saturday with dam
heights above 594 decameters for a good portion of the area. This
high pressure will also suppress the monsoonal moisture flow and keep
it well to our south. The sinking and downsloping air should help
dry and heat up the afternoon atmosphere. Expect high temperatures
ranging from the mid to upper 80s in the interior basins and foot
hills to low to upper 90s north and east of the Laramie Range. Some
locations in Converse and Niobrara Counties could reach or exceed
record daily high temperatures. Another area of concern with the
excessive heat is how dry it will be. Minimum afternoon humidity
values are progged to be in the lower 20s to the low teens and
single digits for the northern and western fire zones. Winds appear
tame and are expected to preclude red flag conditions. A few
isolated storms are possible in the mountains and very southern
portions of the CWA during the afternoon hours with just enough
moisture to kick off high based thunderstorms. Would not expect
these storms to last long or produce much rainfall.

Sunday and Monday still has the ridge axis over the area. There may
be a few weak shortwave troughs that could flatten the ridge
slightly. The probability of a few more afternoon thunderstorms
could result, but chances are low and storms would be dry. The main
concern is for the excessive heat Sunday. Again temperatures soar to
the upper 90s to mid 100s for many locations. The current forecast
is for daily record highs to be broken or tied. Winds do increase
also Sunday with the increasing pressure gradients influenced by the
shortwave troughs. RH values plummet into the single digits over a
large part of the area and overnight recoveries are likely to be
poor. Therefore it is probable red flag products are issued if these
conditions hold in the forecast.

Monday evening through the rest of the forecast period has ensemble
support of a trough clipping the border and extending south through
our area. This would suppress the ridge into the deep southwest and
allow more seasonable conditions to return. Moisture remains a
scarce commodity, but perhaps there is enough along with enhanced
synoptic lift to trigger some showers and storms, especially over
the ranges. Hopefully a cold front associated with this trough can
provide some relief from the heat and increase surface humidity.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1118 AM MDT Wed Jul 29 2026

WYOMING TERMINALS: More thunderstorms and showers develop over the
mountains around 20z to 01z before pushing east this afternoon
into late evening. Heavy to moderate rainfall and gusty winds
are possible for the western terminals (KCYS, KLAR, and KRWL).
Once the thunderstorms and showers move out, expect visibility
and wind speeds to improve.

NEBRASKA TERMINALS: At Nebraska terminals today expect mostly
clear skies through the middle afternoon hour. Starting around
21z storm and shower activity will move in from Wyoming. Periods
of MVFR or IFR conditions could occur at terminals particularly
at KBFF and KCDR. Variable winds gusting to 40 to 45 knots
possible along with reduced visibilities. Activity clears by
about 3 to 5z and sky conditions begin clearing. There is the
possibility of reduced CIGs and visibility post rain, but the
chances are too low to include in TAFs and total surface
saturation appears uncertain.

&&

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

&&

$$

SHORT TERM...MM
LONG TERM...RV
AVIATION...ML/RV