174
ACUS11 KWNS 300358
SWOMCD
SPC MCD 300358
SDZ000-300500-

Mesoscale Discussion 2172
NWS Storm Prediction Center Norman OK
1058 PM CDT Sat Aug 29 2026

Areas affected...north-central into east-central SD

Concerning...Severe potential...Watch unlikely

Valid 300358Z - 300500Z

Probability of Watch Issuance...20 percent

SUMMARY...A large-hail risk will likely continue with elevated
supercells for the next few hours.  The magnitude and spatial extent
of the severe risk will likely remain limited and
localized---precluding the need for a severe thunderstorm watch.

DISCUSSION...Water-vapor imagery shows a lead mid-level shortwave
trough moving into western SD late this evening.  Ascent associated
with this upper feature will combine with modest 850-mb warm
advection across north-central SD extending east-southeast towards
the Huron, SD vicinity.  Radar mosaic during the past hour has shown
both the maintenance and development of additional discrete
supercells.  An overlay of the 00 UTC Rapid City and Aberdeen raobs
showed a moderate to strong buoyancy layer rooted around 700 mb.
Expecting the elevated supercells to be sustained within a more than
adequate buoyancy/shear environment.  Occasional large hail (reports
of 1.75 inches in diameter) will likely continue given the forcing
for ascent that will remain focused over the region.

..Smith/Guyer.. 08/30/2026

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...FSD...ABR...UNR...

LAT...LON   45600214 45770065 45289876 44679812 44289837 44209873
            44409952 44700070 45010211 45280234 45600214

MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN