000
WTNT42 KNHC 181436
TCDAT2
TROPICAL STORM BERTHA DISCUSSION NUMBER  62
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL022008
1100 AM EDT FRI JUL 18 2008

BERTHA HAS A WELL-DEVELOPED CLOUD PATTERN...OCCASIONALLY SHOWING
SIGNS OF TRYING TO FORM AN EYE.  QUIKSCAT DATA FROM EARLIER SUGGEST
MAXIMUM WINDS OF 50-55 KT AND...SINCE SATELLITE CLASSIFICATIONS ALSO
SUPPORT 55 KT...THE INTENSITY IS RAISED TO 55 KT FOR THIS ADVISORY. 
KUDOS GO TO THE GFDL/HWRF MODELS WHICH CORRECTLY FORECAST THE
RE-INTENSIFICATION OF THE STORM.  HOWEVER...SSTS ARE NOW DECREASING
IN THE PATH OF THE STORM...WHICH COULD LIMIT ANY FUTURE GROWTH OF
THE SYSTEM.  IN ABOUT 24 HOURS...SSTS QUICKLY DROP AND VERTICAL
SHEAR IS FORECAST TO INCREASE...SO THIS COMBINATION SHOULD BEGIN A
WEAKENING OF THE STORM.  THE OFFICIAL FORECAST IS CLOSE TO THE
INTENSITY CONSENSUS.

THE INITIAL MOTION OF THE STORM IS 040/16.  THIS GENERAL MOTION WITH
AN INCREASE IN FORWARD SPEED IS EXPECTED AS THE STORM IS CAUGHT
BETWEEN A BUILDING HIGH TO THE SOUTHEAST AND THE MIDDLE-LATITUDE
WESTERLIES.  IN ABOUT 36 HOURS...COLD NORTH ATLANTIC WATERS AND
INTERACTIONS WITH A MIDDLE-LATITUDE TROUGH SHOULD START THE
EXTRATROPICAL TRANSITION PROCESS.  TRACK GUIDANCE IS ABOUT AS
TIGHTLY CLUSTERED AS IT CAN BE AND THE OFFICIAL FORECAST IS CLOSE
TO THE MIDDLE OF THE GUIDANCE.    

 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      18/1500Z 36.2N  52.3W    55 KT
 12HR VT     19/0000Z 38.1N  50.1W    55 KT
 24HR VT     19/1200Z 41.0N  46.8W    55 KT
 36HR VT     20/0000Z 44.2N  43.1W    50 KT...BECOMING EXTRATROPICAL
 48HR VT     20/1200Z 48.0N  38.5W    45 KT...EXTRATROPICAL
 72HR VT     21/1200Z 57.0N  25.5W    45 KT...EXTRATROPICAL
 96HR VT     22/1200Z...ABSORBED
 
$$
FORECASTER BLAKE