989 ACUS11 KWNS 070641 SWOMCD SPC MCD 070641 KYZ000-TNZ000-INZ000-ALZ000-MSZ000-MOZ000-ARZ000-070915- MESOSCALE DISCUSSION 0812 NWS STORM PREDICTION CENTER NORMAN OK 0141 AM CDT WED MAY 07 2003 AREAS AFFECTED...CENTRAL KY...WRN/MID TN...NWRN AL...NRN MS CONCERNING...SEVERE TSTM POTENTIAL...TORNADO WATCH 280... VALID 070641Z - 070915Z LARGE MCS DEVELOPING FROM MERGING SUPERCELLS/BOWS AND TSTM CLUSTERS -- FROM W-CENTRAL KY SWWD ACROSS PORTIONS WRN TN. ADDITIONAL WW MAY BE REQUIRED NEXT 1-2 HOURS AS THIS APPROACHES PORTIONS ERN KY/NERN TN...E OF PRESENT WW. THIS WILL MOVE EWD ACROSS MORE OF CENTRAL KY AND WRN/MID TN OVER NEXT 2-3 HOURS...PRODUCING DAMAGING WIND...LARGE HAIL AND A FEW TORNADOES. DEVELOPMENT OF DISCRETE SUPERCELLS -- WITH ATTENDANT TORNADO AND HAIL POTENTIAL -- REMAINS POSSIBLE AS WELL. MUCAPE 2000-3000 J/KG REMAINS COMMON IN INFLOW-LAYER AIR POCKETS UNMODIFIED BY EARLIER CONVECTION. NUMEROUS MESOSCALE TO STORM SCALE BOUNDARIES -- EVIDENT IN SFC ANALYSIS AND REFLECTIVITY DATA -- SHOULD LOCALLY AID SEVERE POTENTIAL. PREVIOUSLY SEVERE TSTM CLUSTER HAS MOVED EWD OUT OF AL ACROSS PORTIONS NRN GA...MAINTAINING MARGINAL SEVERE WIND/HAIL POTENTIAL WITH PRIMARY HAZARD BEING HEAVY RAINFALL. REF SPC MESOSCALE DISCUSSION 811 FOR MORE DETAILS ON HEAVY RAIN HAZARD THIS REGION. EXPECT TEMPORARY LULL IN SEVERE POTENTIAL NRN AL/NERN MS IN WAKE OF PREVIOUS ACTIVITY...HOWEVER AIR MASS SHOULD DESTABILIZE THROUGH NEXT FEW HOURS IN REGIME OF LOW LEVEL WAA AND 35-50 KT LLJ -- NOW OBSERVED IN PROFILER/VWP DATA -- TRANSPORTING RICH MOISTURE BACK INTO REGION. HENCE...WW SHOULD BE MAINTAINED ACROSS NRN PORTIONS MS/AL IN EVENT OF ADDITIONAL DEVELOPMENT. VWP HODOGRAPHS WITH SFC DATA INPUT SHOW 250-350 J/KG 0-3 KM SRH...AND 40-50 KT 0-6 KM VECTOR SHEAR. ..EDWARDS.. 05/07/2003 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...JKL...LMK...OHX...HUN...PAH...MEG... 34418641 34419061 36888925 36918779 37808752 38348624 38308403