475 
 WTNT42 KNHC 120247
 TCDAT2
  
 TROPICAL DEPRESSION GABRIELLE DISCUSSION NUMBER  15
 NWS NATIONAL HURRICANE CENTER MIAMI FL       AL072013
 1100 PM AST WED SEP 11 2013
  
 DEEP CONVECTION ASSOCIATED WITH GABRIELLE HAS DISSIPATED 
 AGAIN THIS EVENING...LEAVING THE CYCLONE AS A SWIRL OF LOW-LEVEL
 CLOUDS...EXCEPT FOR ONE SMALL THUNDERSTORM THAT HAS RECENTLY
 DEVELOPED WELL EAST OF THE CENTER.  SUBJECTIVE AND OBJECTIVE DVORAK
 INTENSITY ESTIMATES HAVE DECREASED BELOW TROPICAL STORM STRENGTH...
 AND BASED ON THESE DATA THE SYSTEM HAS BEEN DOWNGRADED TO A 30-KT
 TROPICAL DEPRESSION. LITTLE CHANGE IN STRENGTH IS EXPECTED DURING
 THE NEXT 24 HOURS AS THE CYCLONE REMAINS WITHIN AN AREA OF MODERATE
 WESTERLY WIND SHEAR AND DRY MID-LEVEL AIR.  SOME INTENSIFICATION IS
 POSSIBLE AS GABRIELLE INTERACTS WITH A MID- TO UPPER-LEVEL TROUGH
 IN 36 TO 48 HOURS.  THE TROUGH IS EXPECTED TO PROVIDE SOME
 BAROCLINIC FORCING AND SHOULD ALSO CAUSE THE CYCLONE TO BECOME
 EXTRATROPICAL IN ABOUT 2 DAYS.  THE SYSTEM IS LIKELY TO BE ABSORBED
 BY A FRONT OVER NOVA SCOTIA SHORTLY THEREAFTER...HOWEVER A 72-HOUR
 POINT WAS PROVIDED ONCE AGAIN FOR FORECAST CONTINUITY.  WITH THE
 LACK OF DEEP CONVECTION THIS EVENING...AN ALTERNATIVE SCENARIO IS
 THAT GABRIELLE COULD DEGENERATE INTO A REMNANT LOW ON THURSDAY OR
 BECOME AN OPEN TROUGH AS IT BEGINS TO ACCELERATE NORTH-
 NORTHEASTWARD IN A DAY OR SO.
  
 GABRIELLE CONTINUES MOVING SLOWLY WEST-NORTHWESTWARD.  THE CYCLONE
 SHOULD TURN NORTHWARD ON THURSDAY AS IT IS STEERED AROUND THE
 WESTERN PORTION OF A LOW- TO MID-LEVEL RIDGE OVER THE WEST-CENTRAL
 ATLANTIC.  AFTER 24 HOURS...GABRIELLE IS FORECAST TO ACCELERATE
 NORTH-NORTHEASTWARD AHEAD OF THE TROUGH MOVING INTO THE
 NORTHEASTERN UNITED STATES.  THE TRACK GUIDANCE AGREES ON THIS
 SCENARIO AND THE UPDATED NHC TRACK IS ESSENTIALLY AN UPDATE OF THE
 PREVIOUS ADVISORY.
  
 FORECAST POSITIONS AND MAX WINDS
  
 INIT  12/0300Z 33.0N  67.0W   30 KT  35 MPH
  12H  12/1200Z 33.7N  67.6W   30 KT  35 MPH
  24H  13/0000Z 35.7N  67.6W   30 KT  35 MPH
  36H  13/1200Z 39.4N  66.1W   35 KT  40 MPH
  48H  14/0000Z 44.4N  62.8W   40 KT  45 MPH...POST-TROP/EXTRATROP
  72H  15/0000Z 54.5N  50.0W   40 KT  45 MPH...POST-TROP/EXTRATROP
  96H  16/0000Z...ABSORBED BY FRONT
  
 $$
 FORECASTER BROWN