522
FXUS63 KUNR 061007
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
407 AM MDT Sun Jul 6 2025

.KEY MESSAGES...

- Isolated strong to severe thunderstorms are possible today,
  mainly across portions of northeastern WY into southwestern and
  south central SD.

- Additional strong to severe storms may occur Monday.

- Hotter temperatures and drier weather by Tuesday/Wednesday.

&&

.DISCUSSION...(Today Through Saturday)
Issued at 403 AM MDT Sun Jul 6 2025

Current radar imagery shows widespread convection is ongoing over
the CWA. Though the severe threat has greatly diminished, some of
the stronger updrafts have been capable of gusty winds and sub-
severe hail. Showers and storms will continue across western SD
through the morning hours before moving out from west to east
early this afternoon. Right now, it`s looking like the outflow
from this morning`s storms will push the more buoyant airmass to
the south. NAM and HRRR solutions do show some recovery in
southwestern SD, the Black Hills, and portions of northeastern WY
with SB CAPE climbing to above 1000 J/kg by the afternoon. This
could point at some severe potential in those areas later this
afternoon. However, confidence in this forecast remains low as
it`s still unclear how the storms this morning will impact the
environment later this afternoon.

Turning our attention to Monday, another shortwave will cross the
region with low level southerly flow ahead of a sfc trof
advecting moist air into the region. MLCAPE values could
potentially climb above 2000 J/kg through Monday afternoon,
especially across south central SD. Increasing deep layer shear
through the afternoon and evening hours will support organized
convection and supercellular structures. Main concerns with these
storms will be large hail and damaging wind gusts, there is also a
low tornado risk. The major forecast challenge is the timing and
location of the sfc trof and thus the timing and location of the
storms.

Upper ridge builds into the western US by Tuesday/Wednesday,
bringing hotter temperatures and lower chances for precipitation,
though an isolated storm or two can`t be ruled out.

&&

.AVIATION...(For the 06Z TAFS Through 06Z Sunday Night)
Issued At 1023 PM MDT Sat Jul 5 2025

MVFR conditions and gusty winds are expected with thunderstorms
that continue moving across western SD. These storms will
gradually move into central SD overnight, possibly lingering into
Sunday morning. MVFR ceilings have developed over GCC and are
expected to develop over RAP early Sunday morning. By Sunday
afternoon, VFR conditions are expected across the CWA.

&&

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

$$

DISCUSSION/KEY MESSAGES...Wong
AVIATION...Pojorlie