000
WTNT44 KNHC 052046
TCDAT4
HURRICANE IKE DISCUSSION NUMBER  19
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL092008
500 PM EDT FRI SEP 05 2008
 
AN AIR FORCE RECONNAISSANCE PLANE HAS PERFORMED THE FIRST
PENETRATIONS ON IKE AND HAS CONFIRMED THE SATELLITE ESTIMATES.
PEAK FLIGHT LEVEL WINDS OF 109 KT WERE RECORDED...ALONG WITH SFMR
WINDS OF 94 KT...PLUS A DROPSONDE SUGGESTED WINDS OF AT LEAST 95
KT.  A CONSENSUS OF ALL DATA SOURCES SUGGEST SUSTAINED WINDS OF
AROUND 100 KT...SO THIS VALUE WILL BE THE INITIAL INTENSITY.  SOME
WEAKENING COULD OCCUR IN THE NEXT DAY OR SO DUE TO PERSISTENT
NORTHERLY SHEAR.  HOWEVER THIS SHEAR IS FORECAST TO DIMINISH BY
LATE TOMORROW...AND SHOULD ALLOW SOME STRENGTHENING...PERHAPS
RAPID...BY LATE IN THE WEEKEND.  THE OFFICIAL FORECAST IS BASICALLY
AN UPDATE OF THE PREVIOUS ONE...SHOWING AN EXTREMELY DANGEROUS
HURRICANE FOR THE NEXT SEVERAL DAYS.  THIS FORECAST IS IN LINE WITH
LGEM MODEL EARLY ON...AND IS A LITTLE LOWER THAN THE GFDL/HWRF
THEREAFTER.  A BIG UNCERTAINTY IN THE LONG RANGE INTENSITY FORECAST
IS IKE'S POTENTIAL INTERACTION WITH CUBA OR FLORIDA...WHICH COULD
WEAKEN THE HURRICANE MORE THAN SHOWN BELOW.
 
AIRCRAFT AND SATELLITE FIXES SUGGEST A MOTION OF ABOUT 255/13.  A
GRADUAL BEND BACK TOWARD THE WEST IS FORECAST IN A DAY OR
SO AS RIDGING TO THE NORTHWEST OF IKE WEAKENS SOMEWHAT.  ALL
MODELS SUGGEST SOME SORT OF WEAKNESS IN THE RIDGE NEAR FLORIDA IN A
FEW DAYS BETWEEN A RIDGE OVER THE WESTERN ATLANTIC AND THE GULF OF
MEXICO.  THIS WEAKNESS MAY ALLOW A WEST-NORTHWEST OR NORTHWEST TURN
OF THE HURRICANE.  GENERALLY...THE MODELS THAT ARE SHOWING THE
NORTHERNMOST TRACKS...SUCH AS THE GFS/NOGAPS...ARE THE ONES
WEAKENING THE RIDGE TO THE NORTH FASTER.  THE MODELS WITH THE
SOUTHERNMOST TRACKS...SUCH AS THE ECMWF/UKMET/GFDL...SHOW A
STRONGER RIDGE.   OVERALL...MODELS HAVE SHIFTED A LITTLE TO THE
SOUTH...AND I'M GOING TO CONTINUE TO LEAN THE FORECAST IN THAT
DIRECTION.  IF CURRENT TRENDS PERSIST...THE FORECAST COULD BE
SHIFTED FARTHER TO THE SOUTH OR WEST LATER TONIGHT.
 
IT SHOULD BE STRESSED THAT FOUR- AND FIVE-DAY TRACK FORECASTS CAN
HAVE SIGNIFICANT ERRORS...AND ONE SHOULD NOT FOCUS ON THE EXACT
TRACK.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      05/2100Z 22.9N  64.1W   100 KT
 12HR VT     06/0600Z 22.6N  66.2W    95 KT
 24HR VT     06/1800Z 22.2N  68.9W    95 KT
 36HR VT     07/0600Z 22.1N  71.3W   100 KT
 48HR VT     07/1800Z 22.2N  73.7W   110 KT
 72HR VT     08/1800Z 23.0N  78.2W   115 KT
 96HR VT     09/1800Z 24.5N  81.5W   115 KT
120HR VT     10/1800Z 25.5N  83.0W   115 KT
 
$$
FORECASTER BLAKE/BEVEN