651
FXUS63 KUNR 141120
AFDUNR

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

.KEY MESSAGES...

-Hot today with chances for storms returning

-Unsettled conditions Tues-Wed with a significant cool down for
 Wednesday

-Expect a good chance of showers Wednesday for much of the area

-Semi-unsettled and warmer the rest of the week

&&

.DISCUSSION...(Today Through Sunday)
Issued at 110 AM MDT Mon Jul 14 2025

Massive eastern Pac upper ridge will continue to support
downstream unsettled flow with a stronger upper trough arriving by
midweek. Shortwave ridge will support hot temps today, with
triple digit heat returning on parts of the SD Plains. The hottest
temps will be from southwest SD to central SD where highs will
reach the lower 100s. Lee side trough will shift east and provide
the focus for scattered showers and storms late this
afternoon/evening as deeper moisture shifts north into the region.
This will be in addition to isolated terrain forced storms on the
BH. Marginal shear will be in place with sufficient ML CAPE,
allowing for a few pulse strong cells, with gusty winds the main
hazard. Upper impulse will shift east overnight with storm chances
shifting east and waning in the evening. Cool front will shift
south over the region Tues with another set of impulses expected
across the region, supporting chances for showers and storms, best
chances in the afternoon and evening. Southeast of the sfc front
across scentral SD, severe storms will be possible with hires
models indicating a bowing squall line developing there late in
the afternoon. A jet streak will be in the process of shifting
east Tues, supporting increasing bulk shear, which when combined
with ML CAPE over 1000 J/kg will be more than enough to supporting
isolated severe weather across the southern half, again with best
chances across scentral SD south of the front. Strong cold front
will then move through the region with much cooler air expected in
the area by Wed. Highs will be 20 to 30 degrees below seasonal
averages Wed with 50s in the BH (and portions of the Plains) and
60s on much of the Plains. Potent jet streak will advect over the
region, with the diffluent entrance region over the FA, enhancing
lift, with ll theta-e ridging in place. Hence, expect a good
chance of showers and isolated thunderstorms when combined with a
decent cold pool aloft and cyclonic flow. Temps will moderate some
Thur, with things drying out, although low chances for
showers/storms will linger through the weekend given lingering
unsettled westerly flow with sufficient moisture in place.

&&

.AVIATION...(For the 12Z TAFS Through 12Z Tuesday Morning)
Issued At 519 AM MDT Mon Jul 14 2025

VFR conditions will continue through the forecast period.
Isolated to scattered thunderstorms are expected this afternoon
and evening across northeast WY and western SD. Gusty winds can be
expected with any thunderstorms today.

&&

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

$$

DISCUSSION/KEY MESSAGES...JC
AVIATION...JC