Tropical Depression SIXTEEN

ZCZC MIATCDAT1 ALL
TTAA00 KNHC DDHHMM
TROPICAL DEPRESSION SIXTEEN DISCUSSION NUMBER   2
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL162010
500 PM EDT TUE SEP 28 2010
 
THE AIR FORCE HURRICANE HUNTERS FOUND THAT THE LOW-LEVEL CENTER
CONSISTED OF A BROAD AREA OF LIGHT WINDS AND NEARLY UNIFORM
PRESSURE.  INDEED...WINDS WERE 20 KT OR LESS WITHIN 100 N MI OR
MORE OF THE CENTER.  CLEARLY...THIS IS NOT A CLASSICAL TROPICAL
CYCLONE AND THE MAXIMUM WINDS ARE LOCATED SOME 200 N MI SOUTHEAST
OF THE CENTER.  OBSERVATIONS FROM NOAA DATA BUOY 42057 FROM EARLY
THIS MORNING AND ASCAT DATA FROM AROUND 1500 UTC SUGGESTED THAT THE
SYSTEM MAY HAVE BEEN A MARGINAL TROPICAL STORM EARLIER TODAY.  THERE
IS SOME QUESTION...HOWEVER...AS TO WHETHER THOSE WINDS WERE
REPRESENTATIVE OF THE CYCLONE SCALE.  IN ANY EVENT...RECENT
HURRICANE HUNTER DATA SHOWS NO EVIDENCE OF TROPICAL STORM
FORCE WINDS AT THIS TIME.  THE SATELLITE PRESENTATION IS NOT VERY
IMPRESSIVE...WITH RAGGED-LOOKING BANDING FEATURES AND VERY LITTLE
DEEP CONVECTION NEAR THE CENTER.  SOUTH-SOUTHWESTERLY VERTICAL
SHEAR ASSOCIATED WITH A LARGE MID- TO UPPER-LEVEL TROUGH MOVING
OVER THE SOUTHEASTERN UNITED STATES...ALONG WITH THE CURRENT
STRUCTURE OF THE CYCLONE...SHOULD LIMIT INTENSIFICATION OVER THE
NEXT DAY OR SO.   THE OFFICIAL INTENSITY FORECAST IS A LITTLE HIGHER
THAN THE LATEST STATISTICAL/DYNAMICAL LGEM PREDICTION.  GLOBAL
MODEL GUIDANCE INDICATES THAT THE SYSTEM SHOULD MERGE WITH A FRONT
AND BECOME EXTRATROPICAL IN ABOUT 36 TO 48 HOURS.  AFTER THAT...THE
MODELS ALSO SHOW WHAT APPEARS TO BE A NEW BAROCLINIC DEVELOPMENT TO
THE NORTH REPLACING THE FORMER TROPICAL CYCLONE...SO DISSIPATION IS
EXPECTED BY 72 HOURS.
 
BASED ON A BLEND OF THE AIRCRAFT...SURFACE...AND SATELLITE DATA THE
CENTER HAS BEEN RELOCATED SLIGHTLY TO THE WEST OF THE PREVIOUS
TRACK.  NO SIGNIFICANT MODIFICATIONS HAVE BEEN MADE TO THE TRACK
FORECAST OR SYNOPTIC REASONING.  A CONTINUED NORTH-NORTHEASTWARD
MOTION WITH ACCELERATION...BETWEEN THE AFOREMENTIONED TROUGH AND A
MID-LEVEL ANTICYCLONE OVER THE WESTERN ATLANTIC...IS EXPECTED UNTIL
THE SYSTEM DISSIPATES.  THE TRACK FORECAST IS NOW A LITTLE TO THE
EAST OF THE MODEL CONSENSUS BUT QUITE CLOSE TO THE NEW U.K. MET.
OFFICE AND ECMWF GLOBAL MODEL TRACKS.
 
UNLESS THE CIRCULATION OF THE CYCLONE TIGHTENS UP SOON...THE EXACT
TRACK OF THE CENTER ACROSS CUBA AND FLORIDA WILL BE RELATIVELY
UNIMPORTANT...SINCE THE STRONGEST WINDS AND HEAVIEST RAINS WILL
OCCUR WELL REMOVED FROM THE CENTER OVER THE EASTERN SEMICIRCLE.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      28/2100Z 21.5N  82.4W    30 KT
 12HR VT     29/0600Z 23.0N  81.7W    35 KT
 24HR VT     29/1800Z 25.4N  80.6W    40 KT
 36HR VT     30/0600Z 29.0N  79.5W    40 KT
 48HR VT     30/1800Z 34.0N  78.0W    40 KT...POST-TROP/EXTRATROP
 72HR VT     01/1800Z...DISSIPATED
 
$$
FORECASTER PASCH
 
NNNN