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#635325 (Received by flhurricane at: 10:35 AM 29.Sep.2013) TCDAT1 TROPICAL DEPRESSION ELEVEN DISCUSSION NUMBER 3 NWS NATIONAL HURRICANE CENTER MIAMI FL AL112013 1100 AM AST SUN SEP 29 2013 THE DEPRESSION HAS A POORLY ORGANIZED PRESENTATION ON SATELLITE IMAGES THIS MORNING. THE LOW-LEVEL CENTER IS NOT WELL DEFINED AND DEEP CONVECTION IS LIMITED TO A FEW CLUSTERS OF SHOWERS AND THUNDERSTORMS OVER THE NORTHERN SEMICIRCLE AND A NARROW BAND OVER THE EASTERN PORTION OF THE CIRCULATION. DVORAK CLASSIFICATIONS SUPPORT AN INTENSITY OF NO MORE THAN 25-30 KT...SO THE CURRENT INTENSITY IS HELD AT 30 KT. AN UPPER-LEVEL LOW JUST TO THE NORTHWEST OF THE DEPRESSION CONTINUES TO IMPART SOUTHWESTERLY SHEAR...AND THE GLOBAL MODELS SUGGEST THAT THIS REGIME SHOULD CONTINUE FOR THE NEXT 12-24 HOURS. LATER ON...THE DYNAMICAL GUIDANCE INDICATES SOME RELAXATION OF THE SHEAR SO SOME STRENGTHENING IS FORECAST IN A DAY OR SO. THE LATEST GFS RUN DOES NOT SHOW THE SYSTEM WEAKENING IN THE LATTER PART OF THE FORECAST PERIOD...AND THE NEW OFFICIAL FORECAST CALLS FOR THE CYCLONE TO MAINTAIN ITSELF FOR THE NEXT 5 DAYS. THIS IS VERY CLOSE TO THE LATEST INTENSITY MODEL CONSENSUS. THERE IS CONSIDERABLE SPREAD IN CENTER FIXES...AND THE INITIAL MOTION IS AN UNCERTAIN 050/8. A MID-LEVEL RIDGE IS PREDICTED BY THE GLOBAL MODELS TO AMPLIFY TO THE WEST OF THE CYCLONE WITHIN THE NEXT COUPLE OF DAYS...WHICH SHOULD CAUSE THE SYSTEM TO SLOW DOWN AND TURN TOWARD THE RIGHT. THE GFS AND ECMWF GLOBAL MODELS AS WELL AS THE HFIP STREAM 1.5 MODEL CONSENSUS SHOW THE TROPICAL CYCLONE EXECUTING A SMALL CLOCKWISE LOOP DURING THE NEXT FEW DAYS...AND SO DOES THE OFFICIAL TRACK FORECAST. BY LATE IN THE FORECAST PERIOD...A LARGE MID-LEVEL TROUGH APPROACHING FROM THE WEST SHOULD CAUSE THE CYCLONE TO MOVE NORTHEASTWARD. THE NEW NHC TRACK FORECAST IS SIMILAR TO THE PREVIOUS ONE...ALBEIT SHIFTED SLIGHTLY EASTWARD. FORECAST POSITIONS AND MAX WINDS INIT 29/1500Z 26.0N 48.6W 30 KT 35 MPH 12H 30/0000Z 26.7N 47.7W 30 KT 35 MPH 24H 30/1200Z 26.8N 46.8W 35 KT 40 MPH 36H 01/0000Z 26.5N 46.3W 40 KT 45 MPH 48H 01/1200Z 26.5N 47.0W 40 KT 45 MPH 72H 02/1200Z 26.5N 47.5W 40 KT 45 MPH 96H 03/1200Z 27.5N 47.5W 40 KT 45 MPH 120H 04/1200Z 29.5N 45.0W 40 KT 45 MPH $$ FORECASTER PASCH |