Ike keeping his track together as he crosses Cuban mountains

HURRICANE IKE DISCUSSION NUMBER 29

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL092008

500 AM EDT MON SEP 08 2008

CUBAN RADAR OBSERVATIONS INDICATE THAT THE CENTER OF IKE CONTINUES

MOVING WESTWARD OVER CENTRAL CUBA. THE EYE IS STILL VISIBLE BUT

THE EYEWALL IS NOW ENTIRELY OVER LAND AND ITS STRUCTURE HAS DEGRADED

OVER THE PAST FEW HOURS. THE INITIAL INTENSITY IS LOWERED TO 90

KT. THE OFFICIAL FORECAST AGAIN SHOWS LESS WEAKENING OVER LAND

THAN INDICATED BY THE DECAY SHIPS MODEL...IN THE EVENT THAT THE

CENTER EMERGES OVER WATER SOONER THAN FORECAST. IF IKE FOLLOWS THE

FORECAST TRACK IT WILL BE OVER LAND FOR ABOUT 36 HOURS...AND WOULD

ALMOST SURELY BE WEAKER IN THE SOUTHEASTERN GULF THAN SHOWN HERE.

NEVERTHELESS...THE ENVIRONMENT IN THE GULF IS EXPECTED TO BE VERY

CONDUCIVE TO RESTRENGTHENING WITH A VERY DIFLUENT LIGHT SHEAR UPPER

WIND PATTERN AND WARM WATERS BELOW. THE MAJOR UNKNOWN IS HOW

DISRUPTED IKE WILL BE WHEN IT EMERGES.

THERE HAS BEEN NO SIGNIFICANT CHANGE TO THE FORECAST TRACK. IKE'S

TRAJECTORY IS EXPECTED TO BEND GRADUALLY TO THE RIGHT AS THE STORM

NEARS A WEAKNESS IN THE SUBTROPICAL RIDGE OVER THE NEXT COUPLE OF

DAYS...AND THE GUIDANCE MODELS ARE TIGHTLY CLUSTERED THROUGH 72

HOURS. AFTER THAT...THE GFS IS AN OUTLIER IN CALLING FOR A SHARP

SHORT WAVE TROUGH TO MOVE THROUGH THE PLAINS STATES ON DAYS 4-5.

THE GFDL AND HWRF...WHICH USE THE GFS FOR BOUNDARY CONDITIONS...MAY

BE PICKING UP ON THAT AND SHOW A BEND TO THE RIGHT AT THE END OF

THE FORECAST PERIOD. THE OTHER GLOBAL MODELS...SUCH AS THE

ECMWF...SHOW MUCH MORE RIDGING OVER THE EASTERN UNITED STATES AT

THOSE RANGES AND HAVE A MORE WESTWARD TRACK. EVEN THOUGH THE GFDL

HAS PERFORMED VERY WELL WITH IKE SO FAR...I'VE CHOSEN NOT TO ADJUST

THE TRACK EASTWARD GIVEN THAT THE LARGE-SCALE FIELDS IN THE GFS

HAVE NO SUPPORT FROM THE OTHER MODELS. IT IS STILL TOO SOON TO

KNOW WHAT PORTION OF THE GULF COAST WILL ULTIMATELY BE AFFECTED BY

IKE.

FORECAST POSITIONS AND MAX WINDS

INITIAL 08/0900Z 21.2N 77.3W 90 KT...INLAND

12HR VT 08/1800Z 21.6N 79.0W 75 KT...INLAND

24HR VT 09/0600Z 22.4N 81.2W 65 KT...INLAND

36HR VT 09/1800Z 23.1N 83.0W 60 KT...EMERGING INTO GULF

48HR VT 10/0600Z 23.9N 84.5W 75 KT

72HR VT 11/0600Z 25.5N 87.0W 90 KT

96HR VT 12/0600Z 27.0N 90.0W 100 KT

120HR VT 13/0600Z 28.5N 93.0W 100 KT

$$

FORECASTER FRANKLIN