000
WTPZ44 KNHC 281439
TCDEP4
 
TROPICAL STORM ILEANA DISCUSSION NUMBER   4
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP092012
800 AM PDT TUE AUG 28 2012
 
THE CLOUD PATTERN HAS BECOME A LITTLE BETTER ORGANIZED WITH DEEP
CONVECTION IN A LARGE CYCLONICALLY CURVED BAND TO THE WEST OF THE
CENTER.  THE OUTFLOW IS ESTABLISHED IN ALL QUADRANTS. T-NUMBERS
FROM BOTH TAFB AND SAB ARE NOW 3.0 ON THE DVORAK SCALE...SUGGESTING
AN INITIAL INTENSITY OF 45 KNOTS. ILEANA WILL BE MOVING OVER WARM
WATERS AND WITHIN AN ENVIRONMENT OF LOW SHEAR FOR THE NEXT TWO
DAYS. THESE CONDITIONS WOULD FAVOR STRENGTHENING...AND ILEANA IS
FORECAST TO BECOME A HURRICANE DURING THAT PERIOD. AFTER
THAT...WEAKENING SHOULD BEGIN AS ILEANA MOVES OVER LOWER SEA
SURFACE TEMPERATURES.
 
BASED ON CONVENTIONAL SATELLITE AND MICROWAVE FIXES...THE BEST
ESTIMATE OF THE INITIAL MOTION IS 290 DEGREES AT 8 KNOTS. ILEANA IS
LOCATED ON THE SOUTH SIDE OF A SUBTROPICAL RIDGE...BUT IN A COUPLE
OF DAYS...THE CYCLONE WILL BE APPROACHING THE WESTERN EDGE OF THE
RIDGE AND A DEEPENING MID-LATITUDE SHORTWAVE. THIS PATTERN SHOULD
STEER ILEANA ON A TRACK TOWARD THE WEST-NORTHWEST AND NORTHWEST
WITH A DECREASE IN FORWARD SPEED DURING THE NEXT TWO TO FOUR DAYS.
SINCE ILEANA IS EXPECTED TO WEAKEN NEAR THE END OF THE FORECAST
PERIOD...THE CYCLONE IS ANTICIPATED TO TURN MORE TO THE
WEST-NORTHWEST OR EVEN WEST AS IT BECOMES STEERED BY THE LOW-LEVEL
FLOW. THE OFFICIAL FORECAST IS VERY CLOSE TO THE MODEL CONSENSUS
AND NOT TOO DIFFERENT FROM THE PREVIOUS NHC FORECAST.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  28/1500Z 16.0N 109.8W   45 KT  50 MPH
 12H  29/0000Z 16.5N 111.6W   50 KT  60 MPH
 24H  29/1200Z 17.5N 112.8W   55 KT  65 MPH
 36H  30/0000Z 18.5N 114.0W   65 KT  75 MPH
 48H  30/1200Z 19.0N 114.8W   70 KT  80 MPH
 72H  31/1200Z 20.5N 116.0W   60 KT  70 MPH
 96H  01/1200Z 22.0N 119.0W   50 KT  60 MPH
120H  02/1200Z 23.0N 123.0W   35 KT  40 MPH...POST-TROP/REMNT LOW
 
$$
FORECASTER AVILA