Tropical Storm FLORENCE

ZCZC MIATCDAT1 ALL
TTAA00 KNHC DDHHMM
TROPICAL STORM FLORENCE DISCUSSION NUMBER  14
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL062006
1100 PM EDT WED SEP 06 2006
 
AS HAS BEEN THE CASE DURING THE PAST SEVERAL DAYS...THE CENTER OF
FLORENCE REMAINS VERY DIFFICULT TO IDENTIFY.  THE LATEST SATELLITE
POSITION ESTIMATES FROM THE THREE AGENCIES ARE OVER 90 NM
APART...AND THERE HAS NOT BEEN ANY CONCLUSIVE EVIDENCE FROM A
COUPLE OF MICROWAVE OVERPASSES OR SHIP REPORTS.  GIVEN THE LACK OF
A WELL DEFINED CENTER...THE INITIAL MOTION IS A RATHER UNCERTAIN
300/9.  NOTWITHSTANDING OUR LACK OF CONFIDENCE IN THE CURRENT
LOCATION...THE MODEL GUIDANCE REMAINS IN GOOD AGREEMENT ON A
WEST-NORTHWESTWARD TRACK FOR THE NEXT 2 TO 3 DAYS FOLLOWED BY A
TURN TO THE NORTHWEST AND NORTH...AROUND THE PERIPHERY OF A STRONG
MID- TO UPPER-LEVEL HIGH PRESSURE SYSTEM.  MOST OF THE TRACK MODELS
INSIST ON AN INCREASE IN FORWARD MOTION WITHIN THE NEXT 12-24
HOURS.  HOWEVER...THE OFFICIAL FORECAST WILL NOT SHOW AS MUCH
ACCELERATION AND IS CLOSE TO THE SPEED INDICATED BY THE LATEST GFDL
MODEL RUN.  OVERALL...THE OFFICIAL FORECAST TRACK IS IN EXCELLENT
AGREEMENT WITH BOTH THE SIMPLE DYNAMICAL MODEL CONSENSUS AND THE
FSU SUPERENSEMBLE.

DETERMINING THE CURRENT INTENSITY IS ALSO PROBLEMATIC BECAUSE OF THE
AMBIGUITY OF THE CENTER POSITION.  HOWEVER OUR BEST ESTIMATE...
USING THE DVORAK SHEAR PATTERN...INDICATES THAT THE CURRENT WIND
SPEED REMAINS AT 45 KT.  FLORENCE'S CLOUD PATTERN IS SOMEWHAT
AMORPHOUS AND CONTINUES TO LACK DEFINITE BANDING FEATURES...AS
APPARENTLY SOME SOUTHERLY SHEAR IS STILL INFLUENCING THE SYSTEM. 
WATER VAPOR ANIMATION...HOWEVER...SHOWS THAT AN UPPER-LEVEL LOW
LOCATED A FEW HUNDRED MILES WEST OF THE TROPICAL CYCLONE IS SLOWLY
RETREATING WESTWARD.  THIS WOULD CAUSE THE SHEAR TO RELAX AND
PERMIT FLORENCE TO STRENGTHEN.  THE OFFICIAL INTENSITY FORECAST IS
IN GOOD AGREEMENT WITH THE CONSENSUS OF THE SHIPS...GFDL...AND FSU
SUPERENSEMBLE OUTPUT AND SIMILAR TO THAT FROM THE PREVIOUS
ADVISORY...SHOWING A MAJOR HURRICANE LATER IN THE PERIOD.  WE
SHOULD NOTE...HOWEVER...THERE IS LIMITED SKILL IN TROPICAL CYCLONE
INTENSITY PREDICTION PARTICULARLY IN THE 3 TO 5 DAY TIME FRAME.
   
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      07/0300Z 19.6N  52.5W    45 KT
 12HR VT     07/1200Z 20.5N  54.0W    50 KT
 24HR VT     08/0000Z 21.9N  56.7W    55 KT
 36HR VT     08/1200Z 23.1N  59.4W    65 KT
 48HR VT     09/0000Z 24.3N  62.1W    75 KT
 72HR VT     10/0000Z 27.0N  66.0W    90 KT
 96HR VT     11/0000Z 30.0N  67.0W   100 KT
120HR VT     12/0000Z 33.5N  66.5W    95 KT
 
$$
FORECASTER BROWN/PASCH
 
NNNN