517
FXUS63 KUNR 150455
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
1055 PM MDT Mon Jul 14 2025

.KEY MESSAGES...

- Isolated to scattered storms tonight, some storms may be strong
  to severe and capable of large hail and damaging winds.

- Chances for storms continue Tuesday into Wednesday with
  significant cooldown for Wednesday.

- Unsettled and warmer after Wednesday.

&&

.DISCUSSION...(This Evening Through Monday)
Issued at 109 PM MDT Mon Jul 14 2025

Current visible satellite imagery depicts mostly clear skies with
building CU over the northern Black Hills. Temperatures across
the region are in the upper 80s to upper 90s with a few stations
across southwestern SD and the western SD plains reaching the
triple digit mark. Dewpoints across the western SD plains have
climbed into the 50s to low 60s with moderately unstable but
capped airmass developing over the region. The cap should keep
widespread convection from developing through this afternoon with
the exception of the Black Hills where terrain influenced
convergence may be enough to overcome the capping. Marginal deep
layer shear (20-30kt) will be enough to support organized and
high-based convection with deep, well-mixed boundary layers
supporting a damaging wind threat. Increasing height falls ahead
of an approaching shortwave will provide large scale ascent later
this afternoon and evening with widerspread convection as a
result. While shear still looks marginal, the stronger updrafts
could support an isolated hail/wind threat.

Set of impulses ahead of a positively tilted shortwave will move
across the region Tuesday. This will support another round of
storms as a sfc cool front drifts southward through the day.
There`s a chance for severe storms towards south central SD as the
front passes through in the afternoon. Hi-res models still
indicate bowing squall line developing there in the
afternoon/evening.

Strong cold front will move through the region late Tuesday into
Wednesday as upper level trof crosses the Northern Plains. This
will bring much cooler temps (highs in the upper 50s to upper 60s,
which sits at around 20-30 degrees below average for this time of
year). Upper level jet streak moves over the region Wednesday
with the CWA sitting under the diffluent entrance region. This
will provide decent lift and a chance for showers and isolated
storms through Wednesday.

Weak upper level ridging and height rises will help things dry
out on Thursday with warming temperatures. Temperatures will
moderate through this weekend with unsettled westerly flow
supporting at least low chances for showers/storms.

&&

.AVIATION...(For the 06Z TAFS Through 06Z Tuesday Night)
Issued At 1055 PM MDT Mon Jul 14 2025

Showers and thunderstorms will continue overnight across northeast
WY and western SD, then moving into central SD in the late
morning. A cold front will cross the forecast area through the day
on Tuesday, bringing widespread MVFR/IFR CIGS. More storms will
develop late Tuesday into Tuesday evening.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...None.
WY...None.
&&

$$

DISCUSSION/KEY MESSAGES...Wong
AVIATION...13