TROPICAL STORM DEAN DISCUSSION NUMBER 10 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL042007 500 PM EDT WED AUG 15 2007

DEAN CONTINUES TO ORGANIZE THIS AFTERNOON. ALTHOUGH THE CLOUD TOPS
HAVE WARMED RECENTLY...THE LAST FEW VISIBLE SATELLITE PICTURES
INDICATE A TIGHTLY CURVED BAND WRAPPING AROUND THE CENTER. AMSU AND
TRMM MICROWAVE IMAGES HAVE ALSO SUGGESTED THE FORMATION OF A
PARTIAL EYEWALL. MOST OBJECTIVE AND SUBJECTIVE DVORAK INTENSITY
ESTIMATES ARE INCREASING...AND THE CURRENT INTENSITY IS RAISED TO
55 KT.

THE INITIAL MOTION HAS SHIFTED MORE TO THE WEST-NORTHWEST IN THE
PAST SIX HOURS...AROUND 285/19. THIS MOVEMENT TOWARD THE
WEST-NORTHWEST IS EXPECTED TO BE BRIEF AS DEEP-LAYERED RIDGING TO
THE NORTH OF DEAN STRENGTHENS OVERNIGHT...FORCING THE STORM ON MORE
OF A WESTWARD COURSE TOMORROW. THE GLOBAL MODELS NOW SUGGEST THAT
ANY INTERACTION WITH A MIDDLE-LEVEL TROUGH CURRENTLY OVER THE
BAHAMAS WILL BE LIMITED AS THAT FEATURE IS FORECAST TO ADVANCE
WESTWARD AS AN INVERTED TROUGH WELL AHEAD OF DEAN. NUMERICAL TRACK
GUIDANCE IS IN VERY GOOD AGREEMENT WITH THIS SCENARIO...SHOWING THE
STORM IN THE VICINITY OF THE NORTHWESTERN CARIBBEAN SEA IN ABOUT 5
DAYS. THE OFFICIAL FORECAST IS SHIFTED A LITTLE TO THE NORTH DURING
THE FIRST 36 HOURS...BUT IS MUCH FASTER AND TO THE WEST OF THE
PREVIOUS TRACK NEAR THE END OF THE PERIOD. IT IS WORTH NOTING THAT
THE OFFICIAL FORECAST IS STILL SLOWER THAN THE NUMERICAL MODEL
CONSENSUS.

BASED ON WHAT WE THINK WE KNOW ABOUT INTENSITY CHANGE...THERE DO NOT
SEEM TO BE TOO MANY INHIBITING FACTORS TO A FUTURE INTENSIFICATION
OF DEAN. GLOBAL MODELS UNANIMOUSLY DEVELOP A LARGE UPPER-LEVEL
ANTICYCLONE NEAR THE CENTER OF THE HURRICANE AS THE SYSTEM TRAVELS
INTO THE CARIBBEAN SEA. IN COMBINATION WITH VERY DEEP WARM
WATERS...THIS PATTERN WOULD FAVOR THE DEVELOPMENT OF A POWERFUL
HURRICANE. THE OFFICIAL INTENSITY FORECAST IS HIGHER THAN THE
PREVIOUS NHC FORECAST AND IS IN GOOD AGREEMENT WITH A CONSENSUS OF
THE SHIPS...GFDL...HWRF...AND LGEM MODELS.