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| #519795 (Received by flhurricane at: 10:53 PM 20.Jun.2012) TCDAT3 TROPICAL STORM CHRIS DISCUSSION NUMBER 6 NWS NATIONAL HURRICANE CENTER MIAMI FL AL032012 1100 PM AST WED JUN 20 2012 CHRIS HAS HAD WHAT COULD BE CONSIDERED AN EYE FOR THE PAST SEVERAL HOURS. HOWEVER...SUBJECTIVE AND OBJECTIVE SATELLITE INTENSITY ESTIMATES DO NOT SUPPORT ANY SIGNIFICANT CHANGE IN STRENGTH. THE MAXIMUM WINDS ARE THEREFORE BEING KEPT AT 50 KT. EVEN IF CHRIS IS A LITTLE STRONGER...THE CYCLONE IS NOW MOVING OVER SEA SURFACE TEMPERATURES LESS THAN 22C...AND THE MARINE BOUNDARY LAYER COULD BE TOO STABLE TO ALLOW STRONGER WINDS TO BE MIXED TO THE OCEAN SURFACE. THE INITIAL MOTION IS 075 DEGREES AT 19 KT...AND CHRIS WILL LIKELY BEGIN TO DECELERATE AND LOOP COUNTERCLOCKWISE WHILE INTERACTING WITH A DEVELOPING UPPER LOW TO ITS NORTH. THERE IS VERY LITTLE DISPARITY BETWEEN THE TRACK MODELS OVER THE NEXT COUPLE OF DAYS. THE GLOBAL MODELS ALSO SEEM TO AGREE THAT CHRIS WILL BE ABSORBED BY OR MERGE WITH ANOTHER EXTRATROPICAL LOW BY 72 HOURS. THE POST-TROPICAL TRANSITION IS THE TRICKIEST PART OF THE FORECAST. THE FSU PHASE SPACE DIAGRAMS STILL ARGUE THAT CHRIS WILL DEVELOP A DEEPER WARM CORE OVER THE NEXT FEW DAYS. HOWEVER...THE GFS FIELDS SHOW CHRIS BEGINNING TO INTERACT WITH A FRONTAL BOUNDARY TO ITS NORTH IN ABOUT 24 HOURS...ENDING UP ON THE COLD SIDE OF THE BOUNDARY BY 48 HOURS. CHRIS COULD BECOME POST-TROPICAL SOMETIME OVER THE NEXT 24 HOURS IF IT LOSES ITS DEEP CONVECTION...AND IT SHOULD BE INVOLVED WITH THE FRONT ENOUGH TO BE EXTRATROPICAL BY 36 HOURS. THE INTENSITY IS EXPECTED TO CHANGE LITTLE OVER THE NEXT 24 HOURS. GRADUAL WEAKENING SHOULD START WHEN CHRIS BECOMES EXTRATROPICAL. FORECAST POSITIONS AND MAX WINDS INIT 21/0300Z 38.9N 46.4W 50 KT 60 MPH 12H 21/1200Z 40.3N 43.6W 50 KT 60 MPH 24H 22/0000Z 43.0N 42.1W 50 KT 60 MPH...POST-TROPICAL 36H 22/1200Z 44.5N 43.2W 45 KT 50 MPH...POST-TROP/EXTRATROP 48H 23/0000Z 43.8N 45.4W 40 KT 45 MPH...POST-TROP/EXTRATROP 72H 24/0000Z...ABSORBED BY ANOTHER EXTRATROPICAL LOW $$ FORECASTER BERG |
