SPC MD 1585

MD 1585 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR SOUTHERN SOUTH DAKOTA

Mesoscale Discussion 1585
NWS Storm Prediction Center Norman OK
0721 PM CDT Wed Aug 26 2020

Areas affected...Southern South Dakota

Concerning...Severe potential...Watch unlikely 

Valid 270021Z - 270215Z

Probability of Watch Issuance...5 percent

SUMMARY...Ongoing strong to severe storms will continue to pose an
isolated hail and wind threat through sunset. A watch is not
expected.

DISCUSSION...Radar trends over the past couple of hours have shown
additional convective development along the southward propagating
outflow of the initial cluster of supercells that developed in
central SD. Recent IR imagery shows rapid cloud top cooling and an
uptick in lightning activity associated with this newer convection,
indicating that the environment remains unstable with little
inhibition. Recent RAP analyses support this idea with little MLCIN
and nearly 2000 J/kg MLCAPE ahead of the outflow across southern SD.
Effective bulk shear at 40-45 knots also remains favorable for
organized convection. 

Deep layer flow roughly oriented along the outflow boundary may
increase the probability of storm interactions, which could limit
the duration and coverage of the severe threat moving forward.
However, given this environment initially discrete storms should
remain capable a hail and wind threat through sunset when diurnal
cooling will begin to increase inhibition and limit the potential
for sustained mature convection.

..Moore/Guyer.. 08/27/2020

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

ATTN...WFO...ABR...LBF...UNR...

LAT...LON   43440275 43860216 44220089 44190016 43539979 43060003
            42990069 42950155 42970249 43440275 

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