Tropical Storm ILEANA

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TROPICAL STORM ILEANA DISCUSSION NUMBER   5
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP092012
200 PM PDT TUE AUG 28 2012
 
THERE HAS NOT BEEN A SIGNIFICANT CHANGE IN THE OVERALL STRUCTURE OF
THE CLOUD PATTERN IN CONVENTIONAL SATELLITE OR MICROWAVE DATA 
DURING THE PAST SEVERAL HOURS. THE OUTFLOW REMAINS ESTABLISHED AND
THERE ARE CYCLONICALLY-CURVED BANDS WRAPPING AROUND AN AREA OF DEEP
CONVECTION NEAR THE CENTER. T-NUMBERS FROM BOTH TAFB AND SAB
REMAIN AT 3.0 ON THE DVORAK SCALE...INDICATING THAT THE WINDS ARE
STILL 45 KNOTS. ILEANA IS EXPECTED TO REMAIN WITHIN A LOW-SHEAR
ENVIRONMENT BUT WILL BEGIN TO REACH LOWER SEA SURFACE TEMPERATURES
IN ABOUT 3 DAYS. GIVEN THESE CONDITIONS...THE NHC FORECAST CALLS
FOR ILEANA TO BECOME A HURRICANE IN A DAY OR SO AND THEN WEAKEN
GRADUALLY.

THE BEST ESTIMATE OF THE INITIAL MOTION IS 295 DEGREES AT 9 KNOTS
AROUND THE PERIPHERY OF A HIGH PRESSURE SYSTEM CENTERED OVER
WESTERN MEXICO. ILEANA COULD TURN A LITTLE MORE TO THE NORTHWEST AS
A MID-LEVEL TROUGH APPROACHES THE WEST COAST OF THE UNITED STATES.
HOWEVER...SINCE ILEANA IS FORECAST TO WEAKEN BY THE END OF THE
FORECAST PERIOD AND BECOME A SHALLOW SYSTEM...IT COULD TURN MORE TO
THE WEST AS IT BECOMES STEERED BY THE LOW-LEVEL FLOW.  THE OFFICIAL
FORECAST IS CLOSE TO THE CONSENSUS AND LIES IN BETWEEN THE ECMWF
WHICH IS NORTH OF THE GUIDANCE ENVELOPE AND THE GFS/HWRF PAIR TO
THE SOUTH.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  28/2100Z 16.3N 110.7W   45 KT  50 MPH
 12H  29/0600Z 16.9N 111.9W   50 KT  60 MPH
 24H  29/1800Z 18.0N 113.2W   55 KT  65 MPH
 36H  30/0600Z 18.5N 114.0W   65 KT  75 MPH
 48H  30/1800Z 19.5N 115.0W   65 KT  75 MPH
 72H  31/1800Z 20.5N 117.0W   55 KT  65 MPH
 96H  01/1800Z 21.5N 120.0W   45 KT  50 MPH
120H  02/1800Z 22.0N 124.0W   35 KT  40 MPH...POST-TROP/REMNT LOW
 
$$
FORECASTER AVILA
 
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