754 
ACUS11 KWNS 090622
SWOMCD
SPC MCD 090621 
OHZ000-KYZ000-INZ000-090745-

MESOSCALE DISCUSSION 0872
NWS STORM PREDICTION CENTER NORMAN OK
0121 AM CDT FRI MAY 09 2003

AREAS AFFECTED...IND/NRN KY/WRN OH

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 090621Z - 090745Z

THE THREAT OF LARGE HAIL WILL INCREASE ACROSS THE AREA OVER THE NEXT
SEVERAL HOURS. A WW WILL BE REQUIRED SOON.

REGIONAL RADAR DATA INDICATE A LARGE CLUSTER OF ELEVATED TSTMS WITH
A HISTORY OF PRODUCING ISOLATED LARGE HAIL OVER NRN/CNTRL IL MOVING
ENEWD AT AROUND 60KTS. GIVEN THE CURRENT DIRECTION/SPEED...THE
LEADING EDGE OF THESE TSTMS WILL BE MOVING OUT OF WW0315 WITHIN THE
NEXT HALF HOUR.

CURRENT PROFILER/VWP AND RUC ANALYSES SUGGEST STRONG...LOW-LEVEL
WARM/MOIST ADVECTION IS IN PROGRESS ALONG 50-60KT LLJ AXIS TO THE N
OF SURFACE WARM FRONT ACROSS IND ATTM. CONCENTRATED AREA OF PRESSURE
FALLS CURRENTLY NOTED ACROSS IL IS LIKELY A PRODUCT OF THIS WAA
REGIME AS WELL AS DYNAMIC FORCING AHEAD OF INTENSE MID-LEVEL
SHORTWAVE TROUGH LIFTING NEWD INTO IA. THIS DYNAMIC COOLING ATOP THE
LOW-LEVEL MOIST/THERMAL ADVECTION WILL CONTINUE TO DESTABILIZE THE
AIRMASS ACROSS IND INTO NRN KY AND WRN OH OVER THE NEXT SEVERAL
HOURS AS LLJ CONTINUES TO SHIFT EWD.

SUFFICIENT DIRECTIONAL/SPEED SHEAR THROUGH ELEVATED BUOYANCY PROFILE
WILL SUPPORT ORGANIZED TSTMS...INCLUDING A FEW ELEVATED SUPERCELLS
WITH THE POTENTIAL FOR PRIMARILY LARGE HAIL. A NEW WW WILL BE
REQUIRED WITHIN THE HOUR TO THE E AND S OF WW0315.

..MEAD.. 05/09/2003

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...ILN...LMK...IWX...IND...LOT...

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