ZCZC SPCSWOMCD ALL
ACUS11 KWNS 011618 COR
SPC MCD 011618 COR
KYZ000-INZ000-ILZ000-011745-

Mesoscale Discussion 1784
NWS Storm Prediction Center Norman OK
1118 AM CDT Thu Aug 01 2024

Areas affected...portions of southern IL...southern IN...and
western/central Kentucky

Concerning...Severe potential...Watch likely 

Valid 011618Z - 011745Z

CORRECTED FOR TYPO IN GRAPHIC

Probability of Watch Issuance...80 percent

SUMMARY...Thunderstorms coverage and intensity is expected to
increase over the next couple of hours across southern Illinois and
Indiana into parts of western/central Kentucky. Damaging gusts will
be the main concern with activity through the afternoon. A watch
will likely be needed between 17-18z.

DISCUSSION...Thunderstorms are increasing late this morning in the
vicinity of an MCV over southern IL. Visible satellite and surface
obs show an outflow boundary oriented west to east across southern
IL into southern IN ahead of this MCV and developing convection.
Strong heating is already occurring across the downstream airmass,
with temperatures already in the mid/upper 80s along/south of the
outflow. With dewpoints in the 70s, the airmass is quickly
destabilizing and low/midlevel inhibition rapidly eroding. This
should aid in gradually increasing convection (both in coverage and
intensity) over the next couple of hours. 

West/southwesterly, mostly unidirectional wind profiles, with flow
around 30-40 kt in the midlevels, will support eastward developing
storms tracking along the outflow and instability gradient. Upscale
development into a forward propagating MCS is expected, with
damaging gusts being the main concern through the afternoon. While
flow is mostly unidirectional, some enhancement to SRH is possible
in the vicinity of the outflow boundary. Low-level instability is
quite high given the very moist airmass. If a well developed bow
materializes, a tornado or two can not be ruled out via transient
line-embedded mesovortex features, though damaging winds will be the
primary hazard. A severe thunderstorm watch will likely be needed in
the next hour or two.

..Leitman/Gleason.. 08/01/2024

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

ATTN...WFO...ILN...LMK...IND...PAH...ILX...LSX...

LAT...LON   39088896 39528677 39248494 38648474 37698515 37378607
            37298746 37418872 37758946 38188967 38568969 39088896 

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