ZCZC SPCSWODY1 ALL ACUS01 KWNS 052010 SPC AC 052006 STORM PREDICTION CENTER...NWS/NCEP...NORMAN OK DAY 1 CONVECTIVE OUTLOOK...REF AWIPS GRAPHIC PGWE46 KWNS. VALID 052000Z - 061200Z THERE IS A HIGH RISK OF SVR TSTMS ACROSS ERN AR...NRN MS...TN...AND SRN KY TO THE RIGHT OF A LINE FROM 25 NNE CBM 20 S GWO 45 E ELD 40 NE ELD 65 W MEM 25 SSE JBR 40 ENE DYR 20 N BWG 50 SW LEX 30 SSE LEX JKL 45 NW TRI 25 WNW TYS 25 S MSL 25 NNE CBM. THERE IS A MDT RISK OF SVR TSTMS ACROSS EXTREME NERN TX...AR... MS...NWRN AL...KY TO THE RIGHT OF A LINE FROM 15 NE ARG PAH 20 NW LEX 25 S HTS 25 N TRI 15 E CHA 25 NNW BHM 10 SW JAN 25 ENE GGG 45 SE PRX 40 E PRX 55 N HOT 15 NE ARG. THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 15 NNW FYV 40 N POF 25 SE MVN 30 SSE BMG DAY 40 SE FDY 20 NNW ZZV 20 NW BKW 20 NNW SPA 25 S AND 15 ESE AUO 50 SSW LUL 20 SSW ESF 55 NE CLL 25 E ACT 30 SE DAL 15 N PRX 10 NNE MKO 15 NNW FYV. GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 25 NE ERI 30 NNW CXY 25 ENE SBY ...CONT... 15 E JAX 30 WNW CTY ...CONT... 15 NNE GLS 30 NE AUS DAL 10 ESE TUL 65 NW CGI 40 SW FDY 20 SSW ARB 25 WNW JXN MKG. GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 45 NW HVR 25 N REJ 45 S 9V9 25 NNE GRI 45 NNE RSL 15 SSE DDC 15 N EHA 20 WNW LHX 25 NNE COS SNY 25 E RWL 30 SSE WEY 25 W DLN 85 WNW FCA. ...AN OUTBREAK OF TORNADOES...SOME STRONG...IS EXPECTED THIS AFTERNOON AND EVENING FROM ERN AR NEWD ACROSS NRN MS...TN AND SRN KY. ...MID MS/TN VALLEY REGION NEWD INTO KY... AIR MASS REMAINS VERY UNSTABLE ACROSS THE REGION WITH MLCAPE VALUES IN EXCESS OF 3000 J/KG. STORMS ARE ONGOING ACROSS THE AREA AND ARE BEING AIDED BY INCREASING UPPER LEVEL DIFFLUENCE AHEAD OF A SHORTWAVE TROUGH...THAT IS CURRENTLY LOCATED ACROSS NRN TX. THE SHORTWAVE TROUGH IS MOVING ENEWD AT 65 KT AND IF IT MAINTAINS THIS CURRENT SPEED/DIRECTION...WOULD BE LOCATED NEAR MEM AT 06/00Z AND INTO ERN KY BY 06/06Z. THE STRONGEST FORCING SHOULD SPREAD FROM EAST CENTRAL AR NEWD INTO SRN KY THIS AFTERNOON/EVENING. THIS FORCING COMBINED WITH THE STRONG INSTABILITY AND 60-70 KT DEEP LAYER SHEAR WILL RESULT IN NUMEROUS SUPERCELLS. THE DEGREE OF INSTABILITY AND 30 KT OF SHEAR IN THE LOWEST KM INDICATES TORNADOES ARE LIKELY...WITH SOME OF THEM HAVING THE POTENTIAL TO BE QUITE STRONG. ...NRN LA/CENTRAL MS... THE HIGH RISK HAS BEEN LIFTED NWD OUT OF NRN LA AND CENTRAL MS AS 18Z SOUNDINGS SHOWED THE SOUNDINGS ARE CAPPED AND SOME QUESTION TO HOW MUCH LIFTING WILL BE AVAILABLE TO INITIATE STORMS. HOWEVER... STRONG INSTABILITY AND LOW/MID LEVEL SHEAR IS SUFFICIENT FOR SUPERCELLS AND TORNADOES IF STORMS CAN DEVELOP...SO A MODERATE RISK IS MAINTAINED FOR THIS AREA. ...NWRN AR SWD INTO ERN TX... AREA REMAINS VERY UNSTABLE AND SOME ELEVATED CONVECTION HAS DEVELOPED FROM S OF PGO TO ABOUT 50 SE OF DAL. MUCAPE VALUES RANGE FROM 4000 TO 5000 J/KG...BUT THE 18Z SOUNDING AT FTW AND SHV SHOW A STRONG CAPPING INVERSION AROUND 850 MB. STORMS THAT CAN BECOME SURFACE BASED CERTAINLY WOULD BECOME SEVERE AND SHEAR IS STRONG ENOUGH FOR AN ISOLATED TORNADO. STRONG ELEVATED INSTABILITY WILL AT LEAST RESULT IN STORMS WITH SEVERE HAIL. ...AL NEWD INTO ERN TN... CLUSTER OF STORMS ARE CURRENTLY MOVING EWD NRN AL/GA AND ERN TN. AIR MASS HAS STABILIZED SOMEWHAT FROM THIS CONVECTION...BUT SHOULD DESTABILIZE LATE TODAY AS LIFTING INCREASES FROM APPROACHING SHORTWAVE TROUGH. EXPECT CONVECTION TO REDEVELOP ALONG CONVECTIVE BOUNDARIES LATE TODAY/TONIGHT AS LOW LEVEL JET STRENGTHENS AND UPPER SHORTWAVE TROUGH PASSES TO THE NORTH OF THE AREA. LARGE HAIL AND DAMAGING WINDS SHOULD BE THE MAIN THREAT. ..IMY.. 05/05/03 NNNN |