ZCZC SPCSWOMCD ALL
ACUS11 KWNS 032356 
SPC MCD 032356 
SDZ000-WYZ000-040130-

Mesoscale Discussion 1413
NWS Storm Prediction Center Norman OK
0656 PM CDT Mon Jul 03 2023

Areas affected...Southwestern South Dakota

Concerning...Severe Thunderstorm Watch 441...

Valid 032356Z - 040130Z

The severe weather threat for Severe Thunderstorm Watch 441
continues.

SUMMARY...The severe risk continues across Severe Thunderstorm Watch
441 this evening. The primary concern over southwestern South Dakota
is large hail up to 2 inches in diameter in the near-term.

DISCUSSION...Over the Black Hills, latest radar data from KUDX shows
regenerative supercell development near a mesoscale low along an
ENE-WSW-oriented stationary boundary draped across the area. A feed
of high boundary-layer theta-e into this region should continue to
support surface-based inflow for these storms. And, 35-40 kt of 0-6
km shear (per UDX VWP data) in the presence of generally weak
large-scale ascent will favor a continued discrete/semi-discrete
supercell mode. Large hail up to 2 inches in diameter is the main
concern with this activity, though locally severe winds are also
possible. While less certain, a brief tornado cannot be entirely
ruled out, given backed surface winds near the mesoscale low and
related enhancement to boundary-layer streamwise vorticity for the
ongoing supercells.

..Weinman.. 07/03/2023

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

ATTN...WFO...UNR...

LAT...LON   43400387 43760424 44040429 44320417 44560385 44590351
            44580315 44480273 44260247 44120227 43540224 43280252
            43230307 43270355 43400387 

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