Tropical Storm IGOR

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TROPICAL STORM IGOR DISCUSSION NUMBER   3
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL112010
1100 PM AST WED SEP 08 2010
 

IGOR REMAINS A SHEARED TROPICAL CYCLONE. THE MAIN CONVECTIVE CLOUD
MASS IS DISPLACED WEST OF THE PARTIALLY EXPOSED LOW-LEVEL CENTER...
AND THERE IS A SHARP EASTERN EDGE TO THE CENTRAL CONVECTION. IN
ADDITION...THE CLOUD PATTERN HAS BECOME SOMEWHAT LESS ORGANIZED
DURING THE PAST SEVERAL HOURS...WITH CLOUD TOP TEMPERATURES
RECENTLY WARMING. DVORAK INTENSITY ESTIMATES ARE AT 2.5 FROM
TAFB...AND THE 3-HOURLY AVERAGED ADT VALUE IS CLOSE TO 3.0. THE
INITIAL INTENSITY ESTIMATE REPRESENTS A BLEND OF CURRENT INTENSITY
ESTIMATES AND IS UNCHANGED AT 40 KT. THE COMBINATION OF MODERATE TO
STRONG EASTERLY VERTICAL WIND SHEAR AND THE ONGOING INTERACTION OF
IGOR WITH ANOTHER LOW LOCATED 150 N MI TO ITS NORTH IS EXPECTED TO
IMPEDE THE INTENSIFICATION OF THE CYCLONE DURING THE NEXT DAY OR
SO. BEYOND THAT TIME...THE CONSOLIDATION OF IGOR WITH THIS
FEATURE...AS WELL AS A REDUCTION IN THE EASTERLY SHEAR...SHOULD
RESULT IN A STEADY STRENGTHENING.  THE NHC INTENSITY FORECAST IS
SIMILAR TO THE PREVIOUS ADVISORY AND IS CLOSE TO THE LGEM/SHIPS
STATISTICAL-DYNAMICAL INTENSITY GUIDANCE.

THE INITIAL MOTION ESTIMATE IS 270/06. THE FORECAST PHILOSOPHY
REMAINS UNCHANGED. IN THE SHORT-TERM...GLOBAL MODELS SHOW IGOR
INTERACTING WITH AND ABSORBING THE AFOREMENTIONED LOW DURING THE
NEXT 24 HOURS. THIS SHOULD RESULT IN A SLIGHTLY WEAKER SUBTROPICAL
RIDGE TO ITS NORTH AND TEMPORARILY IMPART A WEST-NORTHWESTWARD
MOTION. FROM 24-96 HOURS...A RE-STRENGTHENING OF THE RIDGE IS
FORECAST TO CAUSE IGOR TO TURN MORE WESTWARD. AFTER 96 HOURS...IGOR
IS EXPECTED TO ENCOUNTER A DEVELOPING WEAKNESS IN THE SUBTROPICAL
RIDGE AND TURN WEST-NORTHWESTWARD...SIMILAR TO BUT NOT AS FAR NORTH
AS THE GFDL/HWRF SOLUTIONS. THE NHC OFFICIAL FORECAST TRACK IS
SIMILAR TO THE PREVIOUS ONE IN THE SHORT-TERM...BUT HAS BEEN
ADJUSTED SLIGHTLY NORTHWARD IN LINE WITH THE MULTI-MODEL CONSENSUS
AT LATER FORECAST PERIODS.

 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      09/0300Z 13.8N  24.6W    40 KT
 12HR VT     09/1200Z 14.3N  25.7W    45 KT
 24HR VT     10/0000Z 15.1N  27.9W    50 KT
 36HR VT     10/1200Z 15.8N  30.7W    55 KT
 48HR VT     11/0000Z 16.4N  33.6W    60 KT
 72HR VT     12/0000Z 17.0N  39.0W    75 KT
 96HR VT     13/0000Z 18.0N  43.5W    85 KT
120HR VT     14/0000Z 19.5N  47.5W    90 KT
 
$$
FORECASTER KIMBERLAIN/STEWART
 
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