378
FXUS63 KUNR 011802
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
1202 PM MDT Fri Aug 1 2025

.KEY MESSAGES...

-Unsettled conditions through the weekend

-Isolated strong to severe storms possible at times, including
 today across most of the area

-Areas of smoke from distance wildfires may impact the region at
 times

-Warmer and drier next week

&&

.DISCUSSION...(Today Through Thursday)
Issued at 103 AM MDT Fri Aug 1 2025

Monsoon moisture filled shortwave ridge will slowly advect across
the region next couple of days, supporting near daily chances for
showers and storms. Pos theta-e adv ongoing aloft, supporting
elevated TS from NW through scentral SD this morning. Small hail
and gusty winds will be the main threat from these early morning
storms as the arc of adv shifts northeast through morning. Things
will dry out this afternoon most places with post wave subsidence.
However, the far eastern FA may see continued convention from pos
theta-e adv, with the potential for storms to become sfc based as
some hires models suggest, increasing the potential for strong to
severe storms if they do. The next round of lift and TS chances
will arrive this evening as another impulse traverses the region.
Appreciable ML CAPE of 1500-2500 J/KG will be in place to support
pulse strong/severe storms. Deep layer bulk shear is not the
great, generally around 30 knots. Hence, storms will be outflow
driven. Locally heavy rain will also be possible with expected
slow storm motions and ample deep layer moisture in place.
Seasonally cool temperatures will persist with highs generally in
the 70s once again today, warmest in far west on the other side of
the sudo warm front. Unsettled westerly flow will continue this
weekend with a slow warming trend. Expect continued chances for
showers and storms as a few stronger waves moves through the flow.
However, the timing and strength of these waves will determine
the best period of rain chances as well as the potential for
severe weather, both of which confidence remains low. Coverage of
showers are expected to be scattered at best, typical for early
August in the region. Digging western CONUS trough early next week
will support warmer temps over the Northern Plains and a drying
trend, with the bulk of TS coverage expected to be more isolated.
In addition, western wild fire smoke will traverse the region at
times, offering potential reduced visibility if the smoke makes it
to the sfc.

&&

.AVIATION...(For the 18Z TAFS Through 18Z Saturday)
Issued At 1200 PM MDT Fri Aug 1 2025

Leftover local MVFR conditions will become VFR early this
afternoon. Isolated/scattered showers/thunderstorms will develop
this afternoon over northwestern SD and over northeastern
WY/southwestern SD tonight. Any storm will have local IFR
conditions as well as hail and gusty erratic winds. Have targeted
02/01-03z for the KRAP/KGCC for PROB30 TS given latest model
consensus. Areas MVFR/IFR CIGS may develop over northwestern SD
toward the end of the period.

&&

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

$$

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