805
FXUS63 KUNR 141130
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
530 AM MDT Sat Jun 14 2025

.KEY MESSAGES...

-Fog and low clouds east of the Black Hills again this morning

-Daily chances for thunderstorms, some possibly severe, through
 Monday

-Wet and cooler mid-week, followed by mostly dry and warmer
 weather

&&

.DISCUSSION...(Today Through Friday)
Issued at 315 AM MDT Sat Jun 14 2025

Upper air analysis shows weak ridging across the central/northern
Plains. SW flow persists across the central/northern Rockies ahead
of a stalled Pac NW upper low. This active flow continues across the
western CONUS as several shortwaves cross the northern Plains. KUDX
radar shows a weakening MCS across NW SD continuing eastward. Also,
lingering showers across south central SD over Todd/Tripp counties
will soon be departing the CWA. Low clouds/areas of fog are again
expected early this morning but shouldn`t be as widespread as
yesterday. Warm/moist airmass will persist across the area, with
dewpoints in the low to mid 60s. Highs will reach the upper 70s over
NW SD to near 90 near the Neb border. The next wave will cross the
CWA this afternoon and evening. Convective initiation will take
place along the Bighorns/Laramie mountains and move into NE WY in
the afternoon. CAMs show storms then enter an axis of stronger
instability and minimal CIN centered across the Black Hills. Shear
profiles will be strong enough for supercell development, with large
hail and damaging winds possible. Then as storms move east off the
Black Hills after ~02z through the western SD plains, the threat
transitions more to damaging winds. The 06z HRRR is also suggesting
a secondary line of storms later in the evening coming off the
Bighorns and pushing across NE WY. These storms then reach the
Black Hills area closer to 05/06z before weakening. Initially over
NE WY, these storms could produce both hail and wind, but appear
to be more wind based by late evening as it nears the Black Hills.
Confidence is low with this exact solution & intensity of storms,
but a couple of other CAMs do suggest some secondary precip over
NE WY (though much weaker). With little change to the pattern
through Sunday and Monday, both days should be a general repeat of
today. Storms develop across NE WY in the afternoon, cross the
Black Hills region around 00z, then push east, becoming more wind
based through the evening. An exception on Monday is a cold front
crossing the CWA during the day will limit the best
instability/storms to SW/SCentral SD. Models continue to show a
strong wave crossing the region on Tuesday. Cooler temps in the
upper 60s/70s are expected with more widespread showers/isolated
storms Tue/early Wed. Severe weather is not expected. Generally
drier weather is then expected for the second half of next week,
with above average temps.

&&

.AVIATION...(For the 12Z TAFS Through 12Z Sunday Morning)
Issued At 530 AM MDT Sat Jun 14 2025

IFR conditions (low clouds/fog) will continue this morning across
western South Dakota. Conditions will improve to VFR by late
morning. Thunderstorms will redevelop across northeast WY this
afternoon and Black Hills/western SD plains late afternoon and
evening. MVFR conditions are possible near heavier precipitation.

&&

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

$$

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