Tropical Storm ILEANA
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TROPICAL STORM ILEANA DISCUSSION NUMBER 17
NWS NATIONAL HURRICANE CENTER MIAMI FL EP092012
200 PM PDT FRI AUG 31 2012
THE SATELLITE PRESENTATION OF ILEANA HAS DETERIORATED OVER THE PAST
FEW HOURS...WITH AN OVERALL COOLING OF CLOUD TOPS NEAR THE CENTER
AND SIGNS THAT DRY AIR IS NOW WORKING ITS WAY INTO THE CIRCULATION.
THE INITIAL INTENSITY IS SET TO 60 KT BASED ON A BLEND OF DVORAK
FINAL-T AND CI NUMBERS FROM TAFB AND SAB. STEADY WEAKENING IS
FORECAST AS ILEANA MOVES OVER MUCH COOLER WATERS AND INTO A MORE
STABLE ATMOSPHERE IN THE NEXT COUPLE OF DAYS. THE NEW NHC FORECAST
HAS BEEN ADJUSTED DOWNWARD AND IS NOW A LITTLE BELOW THE INTENSITY
MODEL CONESNUS. ILEANA SHOULD BECOME A REMANT LOW BY 48 HOURS AND
DISSIPATE ENTIRELY BY 5 DAY IF NOT A LITTLE SOONER.
THE INITIAL MOTION ESTIMATE IS 305/7. ILEANA IS EXPECTED TO TURN
MORE WEST-NORTHWESTWARD SOON AS A MID-LEVEL RIDGE BUILDS TO THE
NORTH OF THE CYCLONE. A WESTWARD TURN IS EXPECTED BY 36 HOURS AS
THE WEAKENING TROPICAL CYCLONE IS STEERED PRIMARILY BY THE
LOW-LEVEL FLOW. THE GUIDANCE ENVELOPE HAS SHIFTED A BIT SOUTHWARD
AGAIN THIS CYCLE AND SO HAS THE NHC FORECAST...WHICH WAS ADJUSTED
TOWARD THE NEW TVCE CONSENSUS. THE NEW FORECAST IS A BIT FASTER AND
SHOWS A SOUTHWARD TURN BY DAY 5...FOLLOWING THE TREND OF THE GLOBAL
MODELS.
FORECAST POSITIONS AND MAX WINDS
INIT 31/2100Z 22.4N 116.1W 60 KT 70 MPH
12H 01/0600Z 22.8N 117.2W 50 KT 60 MPH
24H 01/1800Z 23.3N 118.9W 40 KT 45 MPH
36H 02/0600Z 23.6N 120.6W 30 KT 35 MPH
48H 02/1800Z 23.8N 122.3W 25 KT 30 MPH...POST-TROP/REMNT LOW
72H 03/1800Z 24.0N 125.5W 20 KT 25 MPH...POST-TROP/REMNT LOW
96H 04/1800Z 24.0N 128.0W 20 KT 25 MPH...POST-TROP/REMNT LOW
120H 05/1800Z 23.5N 132.0W 20 KT 25 MPH...POST-TROP/REMNT LOW
$$
FORECASTER BRENNAN
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