Official Discussion issued by the National Hurricane Center

IKE (AL092008) DATA RELEASED: 9/2/2008 3:00:00 PM UTC

Copy of official data

TROPICAL STORM IKE DISCUSSION NUMBER   5
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL092008
1100 AM EDT TUE SEP 02 2008

CONVENTIONAL SATELLITE IMAGERY SHOWS THAT IKE HAS A COMPACT AND
WELL-DEFINED CIRCULATION ALTHOUGH DEEP CONVECTIVE BANDING HAS
PRIMARILY BEEN LIMITED TO THE EASTERN SEMICIRCLE. A 0847 UTC
QUIKSCAT PASS REVEALED THAT THE AREA OF TROPICAL STORM FORCE WINDS
HAS EXPANDED A BIT...AND A FEW 50-55 KT BARBS WERE LOCATED WITHIN
THE MAIN CONVECTIVE BAND TO THE NORTHEAST OF THE CENTER. SINCE
DVORAK T-NUMBERS REMAIN 3.0 FROM TAFB AND SAB...THE INITIAL
INTENSITY IS RAISED CONSERVATIVELY TO 50 KT.
MODEL GUIDANCE REMAINS IN EXCELLENT AGREEMENT REGARDING THE TRACK OF
IKE. MOST MODELS...EXCEPT FOR THE GFDN...ARE TIGHTLY CLUSTERED
WITHIN THE FIRST 48 HOURS THEN ONLY SLIGHTLY DIVERGE BEYOND THAT TO
DAY 5. IN FACT...WITH A LATITUDINAL SPREAD OF ONLY 5 DEGREES AT DAY
5...WE COULDN'T HAVE ASKED FOR BETTER AGREEMENT IN THE GUIDANCE.
THE STORM HAS INCREASED IN FORWARD SPEED WITH AN AVERAGE MOTION OF
280/16. THIS GENERAL MOTION IS EXPECTED THROUGH THE FORECAST PERIOD
AS IKE IS STEERED BY A MID-LEVEL HIGH THAT WILL MOVE WEST IN TANDEM
WITH THE CYCLONE. SOME OF THE MODELS... PARTICULARLY THE GFDL AND
HWRF...SHOW A SLIGHT SOUTHWARD BEND AND BRING IKE VERY CLOSE TO OR
OVER HISPANIOLA. HOWEVER...BOTH OF THESE MODELS BRING IKE TO A
MAJOR HURRICANE...AND SINCE THE OFFICIAL INTENSITY FORECAST DOES
NOT CALL FOR SUCH STRENGTHENING...I PREFER TO REMAIN CLOSER TO THE
CONSENSUS OF THE OTHER MODELS.
THE TOTAL PRECIPITABLE WATER PRODUCT INDICATES THAT RELATIVELY DRY
AIR ALMOST COMPLETELY SURROUNDS IKE. GIVEN THE SMALL SIZE OF THE
SYSTEM...IT IS PROBABLY MORE SUSCEPTIBLE TO THE DRY AIR AND WILL
PROBABLY REMAIN SO UNTIL IT CAN DEVELOP JUST ENOUGH DEEP CONVECTION
TO ISOLATE ITSELF. THE STATISTICAL-DYNAMICAL MODELS SUCH AS THE
SHIPS AND LGEM INDICATE GRADUAL INTENSIFICATION TO A HURRICANE
BEFORE NORTHEASTERLY SHEAR INCREASES OVER THE SYSTEM IN 48 HOURS.
THE GFDL AND HWRF APPARENTLY IGNORE SUCH SHEAR AND FORECAST IKE TO
BE A MAJOR HURRICANE IN 3-4 DAYS. WHILE THIS CANNOT BE RULED OUT AS
A POSSIBILITY...THE OFFICIAL FORECAST REMAINS CLOSE TO THE PREVIOUS
FORECAST AND THE INTENSITY CONSENSUS WITH A PEAK INTENSITY OF 90 KT
AS THE SYSTEM APPROACHES HISPANIOLA AND THE SOUTHEASTERN BAHAMAS.

FORECAST POSITIONS AND MAX WINDS

INITIAL      02/1500Z 18.9N  45.0W    50 KT
12HR VT     03/0000Z 19.3N  47.3W    55 KT
24HR VT     03/1200Z 19.9N  50.3W    60 KT
36HR VT     04/0000Z 20.5N  53.5W    70 KT
48HR VT     04/1200Z 21.0N  56.5W    75 KT
72HR VT     05/1200Z 21.5N  62.5W    80 KT
96HR VT     06/1200Z 21.5N  68.5W    85 KT
120HR VT     07/1200Z 21.5N  74.0W    90 KT

$$
FORECASTER BERG/KNABB