000
WTPZ44 KNHC 301445
TCDEP4
 
HURRICANE ILEANA DISCUSSION NUMBER  12
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP092012
800 AM PDT THU AUG 30 2012
 
THE OVERALL ORGANIZATION OF ILEANA HAS INCREASED SLIGHTLY SINCE
OVERNIGHT...WITH A WARM SPOT OCCASIONALLY EVIDENT IN THE CENTRAL
DENSE OVERCAST.  A 1043 UTC AMSU MICROWAVE OVERPASS SHOWS A RAGGED
DOUBLE EYEWALL STRUCTURE OF THE INNER CORE.  DVORAK T-NUMBERS ARE
4.0 FROM TAFB AND 4.5 FROM SAB...AND A BLEND OF THESE SUBJECTIVE
ESTIMATES YIELDS AN INITIAL WIND SPEED OF 70 KT.  THERE IS A SMALL
WINDOW OF OPPORTUNITY FOR SOME SLIGHT STRENGTHENING TODAY.  AFTER
THAT...ILEANA WILL BE MOVING OVER PROGRESSIVELY COOLER WATERS AND
INTO A MORE STABLE ENVIRONMENT.  STEADY WEAKENING SHOULD BE WITHIN
24 HOURS AND ILEANA IS FORECAST TO BECOME A REMNANT LOW IN ABOUT 3
DAYS. 
 
THE HURRICANE HAS BEEN MOVING NORTHWESTWARD AT 7 KT.  THIS GENERAL
MOTION SHOULD CONTINUE DURING THE NEXT DAY OR SO AS ILEANA MOVES
TOWARD A WEAKNESS IN THE SUBTROPICAL RIDGE.  AS THE CYCLONE WEAKENS
AND BECOMES A SHALLOW SYSTEM...IT SHOULD BEND MORE WESTWARD IN THE
LOW-LEVEL FLOW.  HOWEVER...BEYOND 72 HOURS...THE GFS AND ECMWF
REMAIN AT ODDS WITH THE GFS SHOWING A NORTHWESTWARD TRACK...WHILE
THE ECMWF PREDICTS A WESTWARD TO WEST-SOUTHWESTWARD MOTION OF THE
CYCLONE.  THE NHC FORECAST REMAINS BETWEEN THESE EXTREMES...BUT
FAVORS THE MORE CLIMATOLOGICAL WESTWARD MOTION SHOWN BY THE
EUROPEAN MODEL.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  30/1500Z 20.2N 113.7W   70 KT  80 MPH
 12H  31/0000Z 20.9N 114.4W   70 KT  80 MPH
 24H  31/1200Z 21.7N 115.3W   65 KT  75 MPH
 36H  01/0000Z 22.5N 116.4W   55 KT  65 MPH
 48H  01/1200Z 23.3N 117.9W   40 KT  45 MPH
 72H  02/1200Z 24.0N 120.5W   30 KT  35 MPH...POST-TROP/REMNT LOW
 96H  03/1200Z 24.5N 124.0W   20 KT  25 MPH...POST-TROP/REMNT LOW
120H  04/1200Z 25.0N 127.0W   20 KT  25 MPH...POST-TROP/REMNT LOW
 
$$
FORECASTER BROWN