000 WTPZ44 KNHC 300842 TCDEP4 HURRICANE ILEANA DISCUSSION NUMBER 11 NWS NATIONAL HURRICANE CENTER MIAMI FL EP092012 200 AM PDT THU AUG 30 2012 ALTHOUGH THE EYE FEATURE IS NOT APPARENT AT THIS TIME...THE CLOUD PATTERN IS WELL ORGANIZED WITH DEEP CONVECTION NEAR THE CENTER AND A FEW CYCLONICALLY CURVED BANDS. T-NUMBERS FROM TAFB AND SAB ARE 4.0 ON THE DVORAK SCALE...INDICATING THAT THE INITIAL INTENSITY REMAINS AT 65 KNOTS. ALTHOUGH THE ATMOSPHERIC CONDITIONS ARE FAVORABLE FOR INTENSIFICATION...THE CIRCULATION OF ILEANA IS APPROACHING COOLER WATERS. THIS SHOULD RESULT IN GRADUAL WEAKENING...AND ILEANA COULD BECOME A REMNANT LOW IN ABOUT 72 HOURS. THE BEST ESTIMATE OF THE INITIAL MOTION IS 325 DEGREES AT 7 KNOTS. THE CYCLONE IS MOVING AROUND THE WESTERN EDGE OF THE SUBTROPICAL RIDGE AND IS HEADING TOWARD A WEAKNESS CAUSED BY AN EASTWARD-MOVING SHORTWAVE TROUGH. THIS PATTERN SHOULD FAVOR A GENERAL NORTHWEST TRACK FOR THE NEXT 24 TO 48 HOURS. HOWEVER...AS THE TROUGH LIFTS OUT AND ILEANA WEAKENS OVER COOLER WATER...THE CYCLONE SHOULD TURN TOWARD THE WEST AND BECOME STEERED BY THE LOW-LEVEL FLOW AS INDICATED IN THE OFFICIAL FORECAST. IN THE LONG RANGE...THE GFS AND THE ECMWF ARE ONCE AGAIN IN DISAGREEMENT AS IN THE PREVIOUS RUNS. THE GFS INSISTS ON MOVING ILEANA MORE NORTHWARD AHEAD OF THE TROUGH...WHILE THE ECMWF KEEPS INDICATING THAT ILEANA WILL MISS THE TROUGH AND TURN WEST. FORTUNATELY...ILEANA IS FORECAST TO BE A WEAK REMNANT LOW BY THAT TIME PERIOD. FORECAST POSITIONS AND MAX WINDS INIT 30/0900Z 19.7N 113.5W 65 KT 75 MPH 12H 30/1800Z 20.6N 114.2W 65 KT 75 MPH 24H 31/0600Z 21.5N 115.0W 60 KT 70 MPH 36H 31/1800Z 22.3N 116.0W 50 KT 60 MPH 48H 01/0600Z 23.0N 117.0W 40 KT 45 MPH 72H 02/0600Z 24.0N 119.0W 30 KT 35 MPH...POST-TROP/REMNT LOW 96H 03/0600Z 24.5N 122.0W 20 KT 25 MPH...POST-TROP/REMNT LOW 120H 04/0600Z 25.0N 126.0W 20 KT 25 MPH...POST-TROP/REMNT LOW $$ FORECASTER AVILA