DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0105 AM CDT MON MAY 24 2004 VALID 241200Z - 251200Z THERE IS A HIGH RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM P35 25 NNW STJ 40 SSE BIE 25 ENE CNK 35 W BIE 20 NW LNK 20 NNW OMA 35 N DSM 25 NW MLI 35 ESE MLI PIA 45 WSW PIA 40 ENE IRK P35. THERE IS A MDT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 40 N SZL 15 W MKC 15 NW EMP 25 NE HUT 30 ESE RSL 30 S HSI 30 SW OFK 10 NNE SUX 30 WSW MCW 50 NW DBQ 30 W JVL 35 NNE MMO 40 ENE BMI DEC 40 WSW SPI 40 N SZL. THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 20 SW CSM 35 W CSM 40 WNW GAG 40 WNW HLC 15 NW BBW 45 W YKN 10 NNE OTG 15 WSW VOK 15 S MKG 40 NNW MFD 20 ENE PKB 25 SW SSU 25 N HKY AVL 30 SW TYS 30 E BNA 30 WNW HOP 55 NW CGI 45 NNE SGF 30 NW JLN 10 SE PNC 25 NW OKC 25 ESE CSM 20 SW CSM. THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 30 ESE DOV 20 ESE AVP BGM 30 NNE ROC ...CONT... 25 NNW PBG EFK 30 S AUG. GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 40 NW CTB 50 WNW GTF 35 N BZN 50 SW BIL 15 NE SHR 20 N GCC 35 SE 81V 35 NE CDR 55 W VTN 45 SSE PHP 35 ENE DIK 55 NNW ISN ...CONT... 30 E INL 45 ENE DLH 45 ESE RHI 45 NW MBL 20 NE TVC 40 E PLN ...CONT... 60 NNE BML 20 E BHB. GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 25 N DAB 10 SE GNV 35 NW GNV 30 E VLD 45 SE MCN 25 SSW ATL 30 SSW MSL 25 SSW MEM 25 W LIT 25 ESE MLC 25 S ADM 35 NNE BWD 55 SSE DRT ...CONT... 65 SSW MRF 35 WNW MAF 25 N PVW 50 SSW LBL 15 NW LBL 30 W GCK 50 ENE LAA LHX 35 SSE MTJ 45 NNE 4BL 60 E ELY 45 SSW EKO 45 NNW WMC 45 NNE 4LW 50 E SLE 15 ENE OLM 20 ENE BLI. ...THERE IS A HIGH RISK OF SVR TSTMS ACROSS SE NEB...SRN IA...NW IL...FAR NRN MO AND FAR NE KS... ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PARTS OF NE KS...ERN NEB...IA...NRN MO...NRN IL AND FAR SE WI... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE SRN PLAINS...CNTRL PLAINS...UPPER MIDWEST...OH VALLEY...TN VALLEY AND SRN GREAT LAKES... ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE NEW ENGLAND STATES... ...THE SETUP LOOKS FAVORABLE FOR A WIDESPREAD AND SIGNIFICANT SEVERE WEATHER OUTBREAK ACROSS THE LOWER MO VALLEY AND MID MS VALLEY TODAY... ...LOWER MO VALLEY/MID MS VALLEY/CNTRL PLAINS/SRN PLAINS... A PROGRESSIVE SHORTWAVE TROUGH CURRENTLY OVER THE FOUR CORNERS REGION WILL MOVE QUICKLY ENEWD INTO THE CNTRL PLAINS TODAY. A LOW-LEVEL JET WILL CAUSE RAPID MOISTURE TRANSPORT ACROSS THE CNTRL PLAINS WITH LOWER 70 F SFC DEWPOINTS LIKELY REACHING ERN NEB AND SRN IA BY THIS AFTERNOON. THIS WILL RESULT IN EXTREME INSTABILITY WITH MLCAPE VALUES REACHING 5000 J/KG IN THE KC AREA. AS THE SHORTWAVE COMES OUT ACROSS THE CNTRL PLAINS...THE MID-LEVEL JET ASSOCIATED WITH THE SYSTEM WILL PUNCH EWD...SPREADING STRONG DEEP LAYER SHEAR ACROSS THE CNTRL PLAINS AND UPPER MIDWEST. THIS WILL SETUP A FAVORABLE PATTERN FOR A SIGNIFICANT SEVERE WEATHER OUTBREAK TODAY. FORECAST SOUNDINGS FOR SRN IA AND NRN MO LOOK IMPRESSIVE FOR THIS AFTERNOON WITH STRONG LOW-LEVEL DIRECTIONAL SHEAR AND 55 TO 65 KT OF DEEP LAYER SHEAR. THIS COMBINED WITH THE EXTREME INSTABILITY WILL LIKELY BE FAVORABLE FOR TORNADIC SUPERCELLS. THE ETA AND GFS ARE IN GOOD AGREEMENT BACKING SFC WINDS TO THE SOUTHEAST ACROSS NRN MO AND SERN IA. THIS WILL CREATE STRONGLY VEERED LOW-LEVEL WIND PROFILES (0-3 KM SRH OF 400-500 M2/S2). ANY STORMS THAT FORM IN THE HIGHER INSTABILITY ALONG THE WEST EDGE OF THE LOW-LEVEL JET IN THE BACKED SFC FLOW WILL HAVE A POTENTIAL FOR STRONG TORNADOES WITH EVEN A VIOLENT TORNADO POSSIBLE IN THE HIGH RISK AREA. AS THE UPPER-LEVEL SYSTEM MOVES RAPIDLY EWD...A GRADUAL TRANSITION TO A LINEAR STRUCTURE SHOULD OCCUR AND THE WIND DAMAGE POTENTIAL SHOULD DRAMATICALLY INCREASE AS THE LOW-LEVEL JET INTENSIFIES IN THE EVENING. A SWATH OF VERY HIGH WINDS SHOULD OCCUR ACROSS THE HIGH RISK AREA CONSIDERING THE EXTREME INSTABILITY AND HIGH LOW-LEVEL MOISTURE CONTENT AND VERY STEEP LOW-LEVEL LAPSE RATES. A VERY LARGE HAIL THREAT WILL ALSO EXIST ACROSS WRN IA/ERN NEB AND KS AS A PLUME OF VERY STEEP MID-LEVEL LAPSE RATES PUNCHES EWD INTO THE CNTRL PLAINS LATE THIS AFTERNOON. THE SEVERE THREAT SHOULD CONTINUE AFTER MIDNIGHT AS AN MCS FEEDS OFF OF THE STRONG INSTABILITY...MOVING INTO THE OZARK PLATEAU LATE TONIGHT. ...NEW ENGLAND STATES... A SFC LOW AND ATTENDANT COLD FRONT IS FORECAST TO MOVE FROM WEST TO EAST ACROSS THE REGION TODAY. IN ADDITION...AN UPPER-LEVEL TROUGH WILL APPROACH THE REGION FROM THE WEST WHICH WILL PROVIDE SUPPORT FOR WIDESPREAD THUNDERSTORM DEVELOPMENT ACROSS THE NEW ENGLAND STATES BY AFTERNOON. FORECAST SOUNDINGS SHOW MODERATE INSTABILITY (MLCAPE VALUES OF 2000 TO 3000 J/KG) AND 50 TO 60 KT OF DEEP LAYER SHEAR WHICH WILL BE SUFFICIENT FOR SUPERCELLS. THE MAIN THREAT WILL BE WIND DAMAGE CONSIDERING THE 0-2 KM LAPSE RATES SHOULD EXCEED 9.0 C/KM BY 21Z. AN ISOLATED TORNADO MAY ALSO OCCUR ESPECIALLY NEAR THE WARM FRONTAL SFC BOUNDARY AS IT LIFTS NEWD ACROSS ERN NY INTO MA DURING THE LATE AFTERNOON. ...OH AND TN VALLEY... A QUASI-STATIONARY FRONTAL BOUNDARY WILL BE LOCATED ACROSS THE OH VALLEY AND THIS WILL BE A FOCUS FOR CONVECTIVE DEVELOPMENT TODAY. MODEL FORECASTS DEVELOP MODERATE INSTABILITY SOUTH OF THE FRONTAL BOUNDARY WHICH WILL BE SUFFICIENT FOR SEVERE STORMS. FORECAST SOUNDINGS SHOW 500 MB WIND SPEEDS ACROSS THE REGION AROUND 40 KT AND THIS WILL BE SUFFICIENT FOR SEWD MOVING SUPERCELLS. VEERED SFC WINDS AND WEAKENING LOW-LEVEL FLOW DURING THE DAY WILL FAVOR WIND DAMAGE OR HAIL AS THE PRIMARY THREAT. AS THE BOUNDARY LAYER COOLS THIS EVENING...THE SEVERE THREAT SHOULD GRADUALLY DECREASE ACROSS THE REGION. ..BROYLES/GUYER.. 05/24/2004