Chadron, Nebraska 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

376
FXUS65 KCYS 191930
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
130 PM MDT Sun Jul 19 2026

.KEY MESSAGES...

- Hot, dry, and breezy conditions continue through Monday.

- Monsoonal moisture will attempt to return by Tuesday resulting
  in increased precipitation chances through much of the week.

&&

.SHORT TERM /THROUGH MONDAY NIGHT/...
Issued at 1249 PM MDT Sun Jul 19 2026

Typical summertime weather will continue over southeast Wyoming
and western Nebraska throughout the short-term period. The
center of the ridge at 500mb will shift slightly farther south
both this afternoon and tomorrow, generally positioning itself
over the northern Four Corners region. This will allow for a
slight increase in moisture over the mountains of southeast
Wyoming as a bit of monsoonal moisture spills over the top of
the ridge axis. PWAT values will inch upward and as a result, we
can expect a slight increase in shower and thunderstorm coverage
over the Snowy, Sierra Madre, and northern Laramie ranges. Most
thunderstorm activity will remain quite brief and localized,
generally resulting in only a few hundredths of an inch of
liquid. However, a few instances of briefly gusty wind may
accompany the strongest storm cores given DCAPE values above
1500 over most of the Wyoming high country.

The other story will be high temperatures, which will be
slightly enhanced both today and on Monday due to a slight
increase in downslope westerly flow from the west as the ridge
sags to the south. Heat Advisories remain in effect for the
northwest NE panhandle on Sunday, and expand to include areas in
east central Wyoming and most of the NE panhandle on Monday.
Consideration was given to a heat advisory product for Cheyenne
and eastward to Sidney. However, afternoon high temperatures
remain just below the 99th percentile of July highs. If forecast
guidance for tomorrow comes in warmer, an advisory may be
necessitated in the overnight forecast package. Despite the hot
afternoon weather, relatively dry forecast soundings will
result in overnight lows running near to only slightly above
average through the period.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
Issued at 1249 PM MDT Sun Jul 19 2026

Monsoonal moisture arrives in bulk to southeast Wyoming and
western Nebraska by Tuesday and will last throughout much of the
long-term period. The primary reason for the increase in monsoon
moisture will be a lobe of enhanced PWAT values, originating
from the eastern Pacific in the vicinity of a decaying tropical
system drifting north. This, combined with a more favorable
position of the ridge over the southern Four Corners region,
will direct more saturated profiles eastward across the Great
Basin and through the I-80 corridor. After a slight increase in
thunderstorm coverage and chances on Tuesday, the peak of this
surge of moisture will arrive for the convective afternoon
timeframes on Wednesday and Thursday when PWAT normalized
anomalies exceed the 75th percentile of climatology. The
thermodynamic setup combined with relatively light wind speeds
aloft will favor some slow storm motions. Flash flooding will be
possible in areas that see repeated rounds of thunderstorms or
any storms that remain stationary for long periods of time. For
now, the best chances of this appear to be in the higher
elevations of southeast Wyoming as well as the adjacent
foothills of the Snowy, Sierra Madre, and Laramie ranges.
Ultimately, outflow boundary interactions will ultimately
determine where the heaviest rain falls - details that generally
can not be anticipated until the day of the event. Overall,
expect afternoon high temperatures to drop back notably thanks
to increased cloud cover and slightly lower mid-level
temperatures from Tuesday through the end of the week. By Friday
evening and into early next weekend, ensemble guidance suggests
that the monsoonal push will drift eastward and lower PWAT
values will return to the Rockies/High plains. This may
ultimately result in lower precipitation chances and warmer
temperatures by next weekend.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1125 AM MDT Sun Jul 19 2026

VFR is expected to continue for eastern WY and western NE
terminals through midday Monday as clouds bases hold at or above
10kft and visby above 6 SM. The primary aviation weather
concern will be isolated to scattered showers and perhaps
thunderstorms this afternoon and evening. Gusty erratic winds
will accompany any activity, but anticipated coverage precludes
any mention besides VC at this time. Winds should become light
and variable overnight.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...Heat Advisory until 6 PM MDT Monday for WYZ101-102-108.
NE...Heat Advisory until 6 PM MDT Monday for NEZ002-003-019>021-095-
     096.

&&

$$

SHORT TERM...MAC
LONG TERM...MAC
AVIATION...DS