ZCZC SPCSWODY1 ALL ACUS01 KWNS 162005 SPC AC 162004 STORM PREDICTION CENTER...NWS/NCEP...NORMAN OK DAY 1 CONVECTIVE OUTLOOK...REF AWIPS GRAPHIC PGWE46 KWNS. VALID 161300Z - 171200Z THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM VRB 20 SW FMY ...CONT... 10 WSW PIE 45 NNW DAB. GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM PBI 65 W MIA ...CONT... 25 SSW CEW 35 WSW DHN RMG AVL HKY GSO DAN EWR BDR GON ACK. GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM MSO LVM COD RIW RKS DPG TWF BOI 50 ESE BKE S80 MSO. GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 30 S UIL PDX MFR MHS RBL UKI 45 WSW UKI. --- SYNOPSIS --- PROGRESSIVE MIDDLE-UPPER AIR PATTERN OVER CONUS FEATURES STRONG TROUGH --- NOW EVIDENT ON MOISTURE CHANNEL IMAGERY FROM IL SWWD ACROSS SRN PLAINS. THIS FEATURE IS FORECAST TO MOVE EWD TO OH...TN...AL AND N-CENTRAL GULF BY END OF PERIOD...WITH PRONOUNCED VORTICITY MAX AND POSSIBLY CYCLONIC CIRCULATION IN MIDLEVELS OVER AL. THIS SHOULD CONTRIBUTE TO SERN CONUS CYCLOGENESIS/ FRONTOGENESIS ALREADY UNDERWAY. LOW-AMPLITUDE SRN STREAM PERTURBATION IS EVIDENT OVER NWRN GULF AND SHOULD MOVE TO NEAR FL W COAST BY END OF PERIOD. SURFACE CYCLONE NOW ANALYZED OVER ERN TN WILL MOVE SLOWLY EWD INTO SRN APPALACHIANS AND WEAKEN AS MARINE CYCLONE DEVELOPS OFFSHORE CAROLINAS. --- FL --- SCATTERED TSTMS SHOULD CONTINUE MOVING ACROSS AREA IN BAND...WITH A FEW EMBEDDED BOWS POSSIBLE. MAIN THREAT IS DAMAGING WIND. SEVERE THREAT SHOULD DIMINISH THIS EVENING AND TONIGHT ACROSS CENTRAL/NRN FL...AS ISALLOBARIC FORCING ASSOCIATED WITH ATLANTIC CYCLOGENESIS VEERS BOUNDARY LAYER FLOW IN WARM SECTOR AND REDUCES LOW LEVEL CONVERGENCE. VERTICAL SHEAR IS ALREADY WEAKENING PER PRE-STORM TBW/JAX VWP. --- INLAND...SERN AL TO MID ATLANTIC --- WITH INTENSE COLD-AIR DAMMING REGIME IN PLACE E OF APPALACHIANS IN BOUNDARY LAYER...AND STRONG CYCLOGENESIS JUST BEGINNING ALONG ITS PERIPHERY...LARGE AMOUNT OF BAROCLINIC DEVELOPMENT AND FORCING IS EXPECTED TO TAKE PLACE REMAINDER PERIOD. ASSOCIATED INTENSE/ ELEVATED WAA CONVEYOR WILL BE ASSOCIATED WITH LARGE MOISTURE TRANSPORT AS WELL...RESULTING IN SOMEWHAT STEEPENED MIDLEVEL LAPSE RATES AND POTENTIAL FOR AT LEAST ISOLATED THUNDER -- OFTEN ACCOMPANIED BY FREEZING/FROZEN PRECIP -- AS FAR NE AS MID ATLANTIC REGION BY 17/12Z. MEANWHILE...FRONTAL FORCING INTO MARGINALLY UNSTABLE TO NEUTRALLY STABLE AIR MASS MAY LEAD TO ISOLATED TSTMS WITHIN BAND...BUT WEAK LAPSE RATES AND SMALL CAPE SHOULD PRECLUDE ORGANIZED SEVERE THREAT. ..EDWARDS.. 02/16/03 NNNN |