000
WTNT41 KNHC 012045
TCDAT1
TROPICAL STORM FELIX DISCUSSION NUMBER   5
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL062007
500 PM EDT SAT SEP 01 2007
 
THE LAST AIRCRAFT PASS THROUGH THE STORM A FEW HOURS AGO INDICATED
MAXIMUM FLIGHT LEVEL WINDS OF 70 KT AND THE STEPPED FREQUENCY
MICROWAVE RADIOMETER (SFMR) SHOWED 60 KT WINDS AT THE SURFACE. THUS
THE INITIAL INTENSITY IS INCREASED TO 60 KT...AND COULD BE A LITTLE
CONSERVATIVE AS HINTS OF AN EYE FEATURE HAVE BEEN OBSERVED ON
VISIBLE SATELLITE IMAGES.
 
THE INTENSITY FORECAST APPEARS TO BE STRAIGHT-FORWARD.  THE MAIN
QUESTION IS HOW FAST THE STORM WILL INTENSIFY. ALL OF THE GLOBAL
MODELS SHOW AN EXTREMELY FAVORABLE UPPER-ENVIRONMENT AND THE WATERS
OF THE CARIBBEAN SEA ARE VERY WARM. IT IS A LITTLE PUZZLING WHY THE
GFDL/HWRF ARE SO SLOW TO STRENGTHEN THE SYSTEM.  SO FAR...THE
STATISTICAL MODELS HAVE DONE VERY WELL WITH THIS STORM...AND THE
NHC INTENSITY FORECAST IS JUST A LITTLE BELOW THE SHIPS/LGEM
MODELS.  IT IS OF NOTE THAT PROBABILITY OF RAPID INTENSIFICATION...
AS DIAGNOSED BY SHIPS...IS RATHER HIGH.
 
FELIX HAS RESUMED A MOTION OF 280/16 AFTER A BRIEF WESTWARD JOG THIS
MORNING.  A PERSISTENT RIDGE TO THE NORTH OF THE STORM SHOULD STEER
FELIX ON A WEST OR WEST-NORTHWESTWARD TRACK FOR THE NEXT COUPLE
OF DAYS.  THEREAFTER...THE FORECAST HINGES ON HOW STRONG THE RIDGE
REMAINS OVER THE GULF OF MEXICO.  THE UKMET/NOGAPS/GFDL/HWRF ALLOWS
A HIGH OVER THE CENTRAL GULF COAST TO SHIFT EASTWARD NEAR FLORIDA
AND CAUSES A MORE NORTHWESTWARD TRACK OF FELIX IN ABOUT 5 DAYS. 
HOWEVER...THE GFS/ECMWF KEEP THE RIDGE IN PLACE AND MAINTAIN FELIX
ON A WEST OR WEST-NORTHWESTWARD MOTION.  IN GENERAL THE GUIDANCE
HAS SHIFTED A LITTLE FARTHER NORTH FROM SIX HOURS AGO...AND THE
OFFICIAL FORECAST IS NUDGED IN THAT DIRECTION AS WELL.   
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      01/2100Z 12.7N  65.3W    60 KT
 12HR VT     02/0600Z 13.1N  67.9W    70 KT
 24HR VT     02/1800Z 13.8N  71.4W    75 KT
 36HR VT     03/0600Z 14.5N  74.8W    80 KT
 48HR VT     03/1800Z 15.2N  78.2W    90 KT
 72HR VT     04/1800Z 16.3N  83.5W   100 KT
 96HR VT     05/1800Z 17.5N  88.0W   110 KT
120HR VT     06/1800Z 19.5N  92.0W    65 KT
 
$$
FORECASTER BLAKE/AVILA