ZCZC SPCSWOMCD ALL
ACUS11 KWNS 260202 
SPC MCD 260202 
IAZ000-SDZ000-260330-

Mesoscale Discussion 1712
NWS Storm Prediction Center Norman OK
0902 PM CDT Tue Jul 25 2023

Areas affected...portions of eastern South Dakota

Concerning...Severe Thunderstorm Watch 547...

Valid 260202Z - 260330Z

The severe weather threat for Severe Thunderstorm Watch 547
continues.

SUMMARY...The severe threat continues across Severe Thunderstorm
Watch 547. The severe threat is primarily confined to single
supercell storm, capable of producing mainly severe hail and wind.

DISCUSSION...A lone supercell thunderstorm is in progress across
Hand County, SD, which has a history of producing measured severe
gusts and perhaps up to 2 inch diameter hail (per MRMS mosaic radar
data over the past 2 hours). This storm is thriving in an
environment of extreme instability (i.e. 4000+ J/kg MLCAPE per 00Z
mesoanalysis) and 45 kts of effective bulk shear. Furthermore, the
00Z mesoanalysis shows locally higher low-level shear (with modest
low-level hodograph curvature contributing to 200 m2/s2 effective
SRH). Though convective inhibition remains across the warm sector,
this supercell is expected to persist for at least a few more hours
with a continued severe hail and wind threat. A tornado cannot be
completely ruled out given the locally higher low-level shear,
though it is unclear how tornado potential will be impacted by the
CINH and interference of smaller cells merging into the supercell
updraft.

It is questionable whether other storms can develop across Severe
Thunderstorm Watch 547, so the main severe threat should remain with
the ongoing supercell, at least in the near-term.

..Squitieri.. 07/26/2023

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

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

LAT...LON   44829816 45019716 44809651 44079646 43299657 42999692
            43019760 43279860 43469886 43909915 44419906 44639852
            44829816 

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