SPC MD 1809

[NorthGeorgiaWX]

MD 1809 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR EASTERN SOUTH DAKOTA INTO CENTRAL/SOUTHERN MINNESOTA

Mesoscale Discussion 1809
NWS Storm Prediction Center Norman OK
0456 PM CDT Sat Aug 03 2024

Areas affected...eastern South Dakota into central/southern
Minnesota

Concerning...Severe potential...Watch possible 

Valid 032156Z - 040000Z

Probability of Watch Issuance...60 percent

SUMMARY...Severe thunderstorm potential is increasing late this
afternoon across eastern South Dakota into central/southern
Minnesota. Timing for thunderstorm development is uncertain, but
this area is being monitored for possible watch issuance.

DISCUSSION...A surface low is located over north-central MN this
afternoon, with a trailing cold front dropping south across
northeast South Dakota/far southeast North Dakota and west-central
MN. A warm front extends south/southeast from the low over eastern
MN. Between these surface boundaries, a very moist airmass is in
place with dewpoints in the upper 60s to low 70s F. Heating into the
mid 80s to low 90s F has weakened MLCIN, especially across western
portions of the discussion area. Steep midlevel lapse rates near 8
C/km atop the moist boundary layer are contributing to a corridor of
strong instability ahead of the south/southeastward progressing cold
front. Visible satellite imagery shows deepening cumulus near the
front, with some modest development within the broader warm sector. 

Vertically veering wind profiles, with effective shear magnitudes
greater than 35 kt will support organized convection. Initial
supercells capable of large to very large hail are possible. With
time, convection may cluster into a southeastward progressing MCS
later this evening, posing a increasing risk for damaging gusts.
Timing of thunderstorm development remains uncertain, but given
satellite trends, expected storms to develop within the next couple
of hours. Furthermore, at least weak MLCIN will likely persist with
eastward extent. This may confine overall severe potential to a
relatively narrow corridor. This area will continue to be monitored
for possible watch issuance in the next couple of hours.

..Leitman/Smith.. 08/03/2024

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

ATTN...WFO...DLH...MPX...FGF...FSD...ABR...

LAT...LON   46619510 46599635 46339674 46139759 45409821 44919831
            44229800 43709728 43599682 43619607 43629462 43759366
            44349339 45339334 45879351 46269396 46619510 

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