STORM PREDICTION CENTER...NWS/NCEP...NORMAN OK DAY 1 CONVECTIVE OUTLOOK...REF AWIPS GRAPHIC PGWE46 KWNS. VALID 171200Z - 181200Z THERE IS A MDT RISK OF SVR TSTMS ACROSS PORTIONS OF CNTRL/SRN OK AND NCNTRL TX TO THE RIGHT OF A LINE FROM 20 SW END 45 NE OKC 10 W MLC PRX 45 NNW TYR 20 S DAL 10 SE MWL SPS 25 S CSM 30 N CSM 20 SW END. THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 30 NNW LFK 25 SE ACT 25 ESE BWD 50 WSW MWL 25 SW LTS 30 W GAG 55 W GCK 20 W IML 35 SW MHN 15 ENE BUB 30 SW OLU 15 N MHK 40 ENE BVO 25 S FYV 35 SSW HOT 30 ENE SHV 30 NNW LFK. THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM PIE 35 ENE ORL. GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 30 S CRP 35 NW HDO 25 NW JCT 60 NW ABI 40 E PVW 20 S DHT 35 E 4CR 35 ESE SAD 45 NE YUM 35 NW TRM 10 N BFL 30 SW FAT 45 W SAC 55 NW RBL 75 SSW RDM 35 SW DLS 45 NNW DLS 40 SSE YKM 65 N WMC 50 W MLF 30 S PUC 10 NNE VEL 40 SSW RWL 15 NW DGW 40 NE 81V 35 NW Y22 FAR STC 40 ENE DBQ 30 WSW UIN 35 SSE POF 45 W CBM 25 ESE MCN CRE. ...SYNOPSIS... BROAD COLD UPPER TROUGH IS EXPECTED TO EVOLVE INTO A CLOSED LOW OVER THE SRN HIGH PLAINS MONDAY NIGHT AND TUESDAY. MIDLEVEL SHORTWAVE TROUGHS ROUNDING THE BASE OF THIS DEVELOPING CYCLONE WILL EJECT NNEWD INTO THE CNTRL/SRN PLAINS THROUGHOUT THE PERIOD AS VERY STRONG MIDLEVEL JET CORE MOVES INTO NRN MX. DOWNSTREAM...MIDLEVEL TROUGH OVER THE GULF OF MX WILL MOVE NEWD OVER FL AND INTO THE SRN ATLANTIC WATERS BY TONIGHT. AT THE SURFACE...LOW OVER ERN CO WILL DEEPEN WITH A TRAILING DRYLINE MOVING INTO SWRN KS...CNTRL OK... CNTRL TX LINE BY THIS EVENING. ...CNTRL/SRN PLAINS... WARM ADVECTION WILL LIKELY BE DRIVING ELEVATED TSTMS ACROSS PORTIONS OF NW TX AND OK AT THE BEGINNING OF THE PERIOD AS UPPER FLOW BECOMES MORE DIFFLUENT. STRONGEST LARGE SCALE ASCENT APPEARS TO SPREAD NEWD INTO THE CNTRL/SRN PLAINS FROM MIDDAY INTO THE EVENING. UNCERTAINTY EXISTS ON HOW MUCH BOUNDARY LAYER HEATING WILL OCCUR IN WAKE OF MORNING ACTIVITY...BUT THE STRONGEST DESTABILIZATION SHOULD TAKE PLACE ACROSS SWRN OK AND NCNTRL TX WHERE A TRIPLE POINT SHOULD DEVELOP BY EARLY AFTERNOON. SURFACE DEW POINTS IN THE 50S BENEATH COOLING MIDLEVEL TEMPERATURES WILL CONTRIBUTE TO A MODERATELY UNSTABLE AIR MASS...SUPPORTING DEVELOPMENT OF SURFACE BASED TSTMS...PROBABLY EARLY IN THE AFTERNOON. THESE TSTMS WILL DEVELOP RAPIDLY INTO PARTS OF SWRN KS AS WELL. THERE WILL BE A COMPLICATED UPPER FLOW REGIME...OWING TO DEVELOPMENT OF THE UPSTREAM CLOSED LOW. STRONGEST VERTICAL SHEAR WILL BE CONFINED TO AREAS FROM SCNTRL OK INTO NERN TX WHERE POTENTIAL WILL EXIST FOR A FEW SUPERCELLS. FARTHER N...DEEP LAYER SHEAR WILL BE MARGINALLY SUITABLE FOR ORGANIZED SEVERE TSTMS...PROBABLY OF THE LOW TOPPED VARIETY. MAGNITUDE OF LAPSE RATES OVER THE ENTIRE AREA WILL BE CONDUCIVE FOR LARGE HAIL PRODUCTION...WITH A FEW REPORTS OF SIGNIFICANT HAIL POSSIBLE...PARTICULARLY IN THE MDT RISK AREA. THERE COULD ALSO BE A TORNADO OR TWO ACROSS SRN OK AND NCNTRL/NERN TX WHERE SLIGHTLY HIGHER DEW POINTS AND LOW LEVEL DIRECTIONAL SHEAR WILL RESIDE AND ACROSS WRN KS CLOSER TO THE UPPER LOW. TSTMS SHOULD MOVE NNEWD INTO PORTIONS OF THE ARKLATEX...ERN OK...CNTRL KS AND CNTRL NEB DURING THE OVERNIGHT WITH A CONTINUED LARGE HAIL AND ISOLD WIND DAMAGE THREAT. ...CNTRL/SRN FL... LOW AMPLITUDE JET STREAK IS NOTED IN VAPOR IMAGERY...TRANSLATING INTO THE SRN GULF OF MX AROUND SRN PERIPHERY OF UPPER LOW. MCS CURRENTLY MOVING ACROSS THE PENINSULA SHOULD BE EXITING NEWD INTO THE ATLANTIC WATERS EARLY MONDAY MORNING...WITH THE AIR MASS LIKELY DESTABILIZING AGAIN BY AFTERNOON AHEAD OF THE NEXT IMPULSE. IT APPEARS THAT THE BOUNDARY LAYER WILL DESTABILIZE BY AFTERNOON TO ALLOW ADDITIONAL TSTMS TO DEVELOP. 5H TEMPERATURES AROUND MINUS 13C ATOP MID-UPPER 60S DEW POINTS SUGGESTS POTENTIAL FOR SOME HAIL WITH STRONGER UPDRAFTS. DEEP WLY FLOW SUGGEST POTENTIAL FOR SOME SMALL SCALE BOWS WITH LOCAL WIND DAMAGE TOO. ..RACY.. 03/17/03