000
WTNT41 KNHC 132033
TCDAT1
 
TROPICAL STORM FRANKLIN DISCUSSION NUMBER   5
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL062011
500 PM EDT SAT AUG 13 2011
 
AFTER THE MORNING FLARE UP OF DEEP CONVECTION NEAR THE CENTER OF
FRANKLIN...INCREASING VERTICAL SHEAR AND COLDER WATER HAVE STARTED
TAKING THEIR TOLL ON THE CYCLONE THIS AFTERNOON. CONVECTION IS NOW
SHEARED MORE THAN 90 NMI FROM THE CENTER AND THE LOW-LEVEL CENTER
HAS BECOME FULLY EXPOSED. FRANKLIN IS QUICKLY TAKING ON THE
APPEARANCE OF A POST TROPICAL/EXTRATROPICAL LOW PRESSURE SYSTEM.
THE INITIAL INTENSITY IS DECREASED TO 35 KT BASED ON A TAFB
SATELLITE DATA-T NUMBER OF T2.5/35 KT.

THE INITIAL MOTION ESTIMATE IS NOW 070/19. FRANKLIN SHOULD CONTINUE
TO GRADUALLY TURN TOWARD THE EAST AS IT REMAINS EMBEDDED WITHIN
WESTERLY LOW- TO MID-LEVEL FLOW AHEAD OF A MID-TROPOSPHERIC TROUGH.
AS THE CYCLONE WEAKENS AND BECOMES MORE VERTICALLY SHALLOW...
FRANKLIN SHOULD DECELERATE AND BE STEERED TOWARD THE EAST-SOUTHEAST
BY WEAKER LOW-LEVEL FLOW IN THE LATTER FORECAST PERIODS. THE NHC
FORECAST TRACK IS SIMILAR TO BUT SLIGHTLY SOUTH AND SLOWER THAN THE
PREVIOUS ADVISORY...AND CLOSELY FOLLOWS THE NHC DYNAMICAL MODEL
CONSENSUS.
 
FRANKLIN IS CURRENTLY OVER 25C SST WATER AND COOLER WATER LIES AHEAD
OF THE CYCLONE FOR AT LEAST THE NEXT 36 HOURS. THE COMBINATION OF
INCREASING WESTERLY VERTICAL WIND SHEAR AND COLDER WATER SHOULD
INHIBIT THE DEVELOPMENT OF ANY SIGNIFICANT DEEP CONVECTION NEAR THE
EXPOSED LOW-LEVEL CENTER. AS A RESULT...FRANKLIN COULD BECOME FULLY
EXTRATROPICAL WITHIN THE NEXT 12 HOURS OR SO. THE POST-TROPICAL
REMNANT LOW IS THEN EXPECTED TO MERGE WITH A COLD FRONT IN 24
HOURS...AND IT STILL APPEARS THAT THERE WILL NOT BE ENOUGH
BAROCLINIC ENERGY TO CAUSE FRANKLIN TO RE-STRENGTHEN AS A
SIGNIFICANT EXTRATROPICAL LOW PRESSURE SYSTEM. THE INTENSITY
FORECAST IS SIMILAR TO THE PREVIOUS ADVISORY AND REMAINS LOWER THAN
ALL OF THE NHC INTENSITY GUIDANCE.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  13/2100Z 39.7N  55.5W   35 KT  40 MPH
 12H  14/0600Z 40.2N  51.9W   35 KT  40 MPH...POST-TROP/EXTRATROP
 24H  14/1800Z 40.3N  47.0W   35 KT  40 MPH...POST-TROP/EXTRATROP
 36H  15/0600Z 39.9N  43.3W   30 KT  35 MPH...POST-TROP/EXTRATROP
 48H  15/1800Z 38.8N  40.7W   30 KT  35 MPH...POST-TROP/EXTRATROP
 72H  16/1800Z...DISSIPATED
 
$$
FORECASTER STEWART