Mesoscale Discussion 0245
NWS Storm Prediction Center Norman OK
0225 PM CDT Wed Mar 19 2025
Areas affected...parts of southern Illinois and Indiana...western
Kentucky
Concerning...Severe potential...Watch possible
Valid 191925Z - 192130Z
Probability of Watch Issuance...60 percent
SUMMARY...Thunderstorm development east of the Mississippi River,
into areas south of the Ohio River, appears increasingly possible by
5-7 PM CDT, if not a bit earlier. This may include the evolution of
a broken line with embedded supercells, posing at least the risk for
severe hail and wind.
DISCUSSION...From around the Greater St. Louis area southward,
convective development along the dryline still appears suppressed by
mid-level subsidence and warming to the east and south of the
intense cyclonic mid-level jet nosing through the middle Mississippi
Valley. However, better low-level moisture return (characterized by
mid 50s F surface dew points) is ongoing across the Missouri
Bootheel and adjacent portions of western Kentucky through southern
Illinois. As this continues, coincident with the eastward
progression of the mid-level trough, it appears that mid-level
forcing for ascent and cooling aloft may gradually overcome
inhibition and support increasing thunderstorm development, perhaps
into areas south of the Ohio River by early evening.
Rapid Refresh forecast soundings indicate considerable strengthening
and enlargement of the low-level hodographs around this same time,
though perhaps with a tendency for the hodographs to trend more
linear as thunderstorms finally initiate with the removal of the
mid-level inhibition. Regardless, strong deep-layer shear will be
supportive of organized convection, including supercells, with
potential to produce at least severe hail and wind.
..Kerr/Leitman.. 03/19/2025
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...LMK...OHX...IND...PAH...
LAT...LON 36788895 38078861 38888669 38518637 37378714 36618804
36788895
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