DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1144 AM CST WED MAR 03 2004 VALID 041200Z - 051200Z THERE IS A MDT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 30 ENE SJT 15 NNE ABI 25 WSW SPS 40 NNW ADM 30 N MLC 20 W FSM 30 WNW HOT 10 NE TXK 25 N GGG 50 SSW TYR 30 NNW CLL 20 SW AUS 25 NE HDO 50 SSW JCT 40 S SJT 30 ENE SJT. THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 25 SSE P07 40 S MAF 10 NNE LBB 50 E AMA 20 N END 25 NNW IRK 25 SW RFD 15 N CGX SBN 15 E IND 35 N HOP 30 SSW ESF 25 ENE VCT 60 WSW COT. GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 15 E CRP 15 SSE LRD ...CONT... 10 SW ELP 20 NE DMN 40 N FHU 70 E PHX 25 SSW INW 60 WNW GUP 45 W FMN 20 S DRO 35 SSE ALS 20 SSW TAD 50 NNW CAO 15 WSW EHA 30 ESE LBL 20 W P28 10 ESE SLN 25 NNE MHK 25 NE FNB 10 E DSM 20 NNW LNR 45 NW MKG 35 NE MKG 25 WNW FNT 20 ENE DTW ...CONT... CLE 20 E CMH 45 WNW HTS 20 SW LEX 10 S BNA 45 N MEI 50 SE 7R4. ...THERE IS A MDT RISK OF SVR TSTMS ACROSS PORTIONS OF CNTRL TX...SERN OK..AND WRN AR... ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE SRN PLAINS TO THE MIDWEST... ...SYNOPSIS... STRONG UPPER LOW...NOW BEGINNING TO TRANSITION EWD FROM THE NRN GULF OF CA...IS FCST TO EJECT NEWD FROM NRN MEXICO TO THE UPPER MS VALLEY THROUGH THE DAY 2 PERIOD. POWERFUL MID LEVEL WIND MAX OF 90-110KT IS EXPECTED TO SPREAD ACROSS TX EARLY IN THE PERIOD AND THEN ACCELERATE NEWD TO THE MIDWEST BY EARLY FRIDAY AS MID LEVEL HEIGHT FALL CENTER ...NEARING 200M/12H...TRANSLATES NEWD FROM NWRN TX TO IA. LATEST NCEP-SREF MEAN INDICATES DEEPENING SURFACE LOW WILL CONSOLIDATE OVER OK LATE TOMORROW AND THEN TRACK TO NRN IL BY FRIDAY MORNING. AS THIS OCCURS...VERY MOIST WARM SECTOR SHOULD EXPAND FROM THE SRN PLAINS AND MIDDLE MS VALLEY TO THE LOWER OH VALLEY AND AID WIDESPREAD AND VIGOROUS TSTM DEVELOPMENT AHEAD OF SURGING DRY LINE AND COLD FRONT. MAGNITUDE OF THE LARGE SCALE FORCING FOR ASCENT...COUPLED WITH THE ANTECEDENT MOIST BOUNDARY LAYER AIRMASS ACROSS MUCH OF SCNTRL TX AND EXPANDING INTO THE ARKLATEX...SUGGESTS THE POTENTIAL FOR A WIDESPREAD AND POSSIBLY SIGNIFICANT SEVERE WEATHER EVENT UNFOLDING ON THURSDAY. ...TX/SERN OK/WRN AR... CLUSTERS OF STRONG TO SEVERE STORMS MAY BE ONGOING EARLY IN THE PERIOD ACROSS PORTIONS OF WEST TX AS POWERFUL UPPER TROUGH BEGINS TO SPREAD ENE FROM NRN MEXICO. STRENGTH OF THE DEEP LAYER SHEAR... FORCING...AND STEEP LAPSE RATES ACROSS THE REGION WILL FAVOR SUPERCELLS WITH LARGE HAIL AND PERHAPS STRONG WINDS. DOWNSTREAM WARM SECTOR AIRMASS MAY BE SLOW TO DESTABILIZE DEPENDING ON CLOUD COVER AND EXTENT OF PRECIPITATION PRECEEDING THE UPPER TROUGH AND FORCING. HOWEVER...DESPITE THESE UNCERTAINTIES...GRADUAL DESTABILIZATION ASSOCIATED WITH DIURNAL HEATING AND EMERGING HEIGHT FALLS/LIFT SHOULD RESULT IN SUFFICIENTLY MOIST AND UNCAPPED PROFILES TO SUPPORT SURFACE-BASED STORMS BY AFTERNOON. LATEST INDICATIONS SUGGEST THAT SHEAR...INSTABILITY...AND FORCING IN A CORRIDOR FROM THE HILL COUNTRY TO THE ARKLATEX AND SERN OK WILL BECOME INCREASINGLY SUPPORTIVE OF SUPERCELLS WITH LARGE HAIL...DAMAGING WINDS...AND TORNADOES FROM LATE MORNING INTO THE EVENING. DEGREE OF SHEAR ACROSS THIS REGION COULD RESULT IN LONG-LIVED STORM ROTATION WITH THE POTENTIAL FOR CYCLIC AND FAST MOVING SUPERCELLS WITH A COUPLE OF STRONG TORNADOES. THIS ACTIVITY MAY INITIALLY BE DISCRETE AHEAD OF A STRONG DRYLINE SURGE...OR SEVERE STORMS MAY BE EMBEDDED WITHIN A STRENGTHENING LINE OF CONVECTION AHEAD OF SURGING DRYLINE. ...AR/MO TO IL/IND... ACTIVITY SHOULD EVENTUALLY CONSOLIDATE INTO A SEVERE SQUALL LINE ON THE NOSE OF 100KT MID LEVEL JET AND STRONG MID LEVEL DRY INTRUSION DURING THE EVENING. WHILE THIS CONVECTION WILL LIKELY RACE NEWD INTO SOMEWHAT MARGINAL INSTABILITY...STRENGTH OF FORCING AND WIND FIELDS SHOULD CONTINUE TO RESULT IN DAMAGING WIND EVENTS...AND POSSIBLY SCATTERED TORNADO REPORTS...THROUGH MUCH OF THE NIGHT FROM AR/MO TO THE MID MS VALLEY. ...CNTRL OK TO OZARKS... WHILE TORNADO/WIND PROBABILITIES SHOULD BE HIGHER OVER TX AND THE RED RIVER AREA THROUGH EVENING...STRONG FORCING ASSOCIATED WITH THE DEEPENING SURFACE LOW WILL ALSO FAVOR SUPERCELLS WITHIN A WEAKLY UNSTABLE ENVIRONMENT. STRONG MIDLEVEL COOLING ACROSS THIS REGION WITHIN THE SYSTEM COMMA-HEAD SHOULD SUPPORT LARGE HAIL...AND PERHAPS WIND DAMAGE AND ISOLD TORNADOES DURING THE FIRST HALF OF THE PERIOD. ..CARBIN.. 03/03/2004