000
WTNT44 KNHC 030251
TCDAT4
TROPICAL STORM IKE DISCUSSION NUMBER   7
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL092008
1100 PM EDT TUE SEP 02 2008
 
THE OVERALL CLOUD PATTERN IS A LITTLE MORE SYMMETRIC AND THE OUTFLOW
IS EXCELLENT IN ALL QUADRANTS. HOWEVER...IKE LACKS AN INNER CORE
AND DEEP CONVECTION IS LIMITED TO A CYCLONICALLY CURVED BAND MAINLY
TO THE WEST OF THE CENTER.  AN EARLIER QUIKSCAT PASS DID NOT SHOW
ANY WINDS HIGHER THAN 45 KNOTS BUT DVORAK T-NUMBERS CONTINUE TO
SUGGEST THAT THE WINDS ARE 55 KNOTS..AND THIS NUMBER IS USED FOR THE
INITIAL INTENSITY.  SINCE THE SHEAR IS EXPECTED TO BE LIGHT FOR A
DAY OR SO...A GRADUAL INTENSIFICATION IS FORECAST AND IKE COULD
BECOME A HURRICANE ANYTIME SOON.  IN 2 TO 3 DAYS... A STRONG
EASTERLY SHEAR IS FORECAST TO DEVELOP AND COULD DELAY THE
INTENSIFICATION PROCESS.  HOWEVER...EASTERLY SHEAR IS NOT AS
NEGATIVE AS WESTERLY SHEAR FOR A CYCLONE TO INTENSIFY. ALTHOUGH
BOTH GFDL AND HWRF MAKE IKE AN INTENSE CYCLONE IN THE VICINITY OF
THE BAHAMAS IN FIVE DAYS...THE OFFICIAL FORECAST IS MORE
MODERATE...AND IS A BLEND OF THE SHIPS AND THE DYNAMICAL MODELS.

IKE IS SOUTH OF A STRONG SUBTROPICAL RIDGE AND IS MOVING TOWARD THE
WEST-NORTHWEST OR 285 DEGREES AT 15 KNOTS. GLOBAL MODELS EXPAND AND
BUILD THE RIDGE WESTWARD...AND THIS PATTERN SHOULD FORCE IKE ON A
GENERAL WESTWARD TRACK. THE RIDGE BECOMES SO STRONG BY THE END OF
THE FORECAST PERIOD THAT MODELS TURN IKE ON A SLIGHT WEST-SOUTHWEST
TRACK. THIS SHIFT IS REFLECTED IN THE OFFICIAL FORECAST.  WITH THE
EXCEPTION OF THE UK MODEL...WHICH MOVES IKE WITH A MORE
WEST-NORTHWEST TRACK...THE REST OF THE GUIDANCE IS TIGHTLY
CLUSTERED PLACING THE CYCLONE IN THE SOUTH/CENTRAL BAHAMAS IN FIVE
DAYS. THE FACT THAT MOST OF THE DYNAMICAL MODELS ARE IN GOOD
AGREEMENT INCREASES THE CONFIDENCE IN THE TRACK FORECAST. 

 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      03/0300Z 19.9N  47.9W    55 KT
 12HR VT     03/1200Z 20.3N  50.3W    65 KT
 24HR VT     04/0000Z 21.0N  53.5W    70 KT
 36HR VT     04/1200Z 22.0N  56.5W    75 KT
 48HR VT     05/0000Z 22.5N  59.5W    80 KT
 72HR VT     06/0000Z 22.5N  64.5W    85 KT
 96HR VT     07/0000Z 22.5N  70.0W    90 KT
120HR VT     08/0000Z 22.1N  76.0W    95 KT
 
$$
FORECASTER AVILA