000
WTNT44 KNHC 020835
TCDAT4
 
TROPICAL STORM NADINE DISCUSSION NUMBER  79
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142012
500 AM AST TUE OCT 02 2012

THE STORM IS MAINTAINING A RING OF MODERATE DEEP CONVECTION AROUND A
RAGGED EYE-LIKE FEATURE.  SUBJECTIVE DVORAK INTENSITY ESTIMATES ARE
55 KT FROM BOTH TAFB AND SAB...AND SO THE ADVISORY INTENSITY IS
KEPT AT 55 KT.  THE TROPICAL CYCLONE REMAINS IN A REGION OF
RELATIVELY LOW VERTICAL SHEAR NEAR THE AXIS OF AN UPPER-LEVEL
TROUGH.  HOWEVER AS NADINE BEGINS TO MOVE NORTHEASTWARD AND
NORTH-NORTHEASTWARD...WESTERLY SHEAR IS LIKELY TO INCREASE...AND
AFTER 48 HOURS THE CYCLONE SHOULD BE MOVING OVER WATER TEMPERATURES
BELOW 20 DEG C.  GRADUAL WEAKENING IS FORECAST OVER THE NEXT 2-3
DAYS...AND THE NHC INTENSITY FORECAST IS FAIRLY CLOSE TO THE
INTENSITY MODEL CONSENSUS.  BY 72 HOURS...GIVEN THE EXPECTED COLD
SSTS...NADINE IS LIKELY TO HAVE UNDERGONE THE TRANSFORMATION INTO
A POST-TROPICAL CYCLONE.  GLOBAL MODELS SHOW THE SYSTEM BECOMING
FRONTAL IN NATURE BY 96 HOURS...SO THE CYCLONE IS SHOWN AS
EXTRATROPICAL BY THAT TIME.  BY THE END OF THE FORECAST
PERIOD...THE SYSTEM IS PREDICTED TO BECOME ABSORBED BY...OR TO
MERGE WITH...A LARGE EXTRATROPICAL LOW PRESSURE SYSTEM OVER THE
NORTH ATLANTIC. 
 
NADINE IS GRADUALLY TURNING EASTWARD...AND THE MOTION IS NOW AROUND
105/6.  FEW CHANGES HAVE BEEN MADE TO THE PREVIOUS TRACK
FORECAST...AND THE SYNOPTIC REASONING REMAINS ABOUT THE SAME.  A
VIGOROUS MID-TROPOSPHERIC TROUGH CURRENTLY NEAR NEWFOUNDLAND IS
FORECAST TO DROP SOUTHEASTWARD AND RESULT IN A LARGE AND STRONG
DEEP-LAYER EXTRATROPICAL CYCLONE TO THE WEST OF THE AZORES IN A FEW
DAYS.  NADINE SHOULD TURN NORTHEASTWARD AND NORTH-NORTHEASTWARD IN
THE FLOW ON THE EASTERN SIDE OF THIS CYCLONE DURING THE NEXT 3 DAYS
OR SO.  AFTERWARDS...IF POST-TROPICAL NADINE HAS STILL MAINTAINED
ITS IDENTITY...IT SHOULD TURN NORTHWESTWARD AND MOVE AROUND THE
NORTHERN PORTION OF THE LARGER CYCLONE UNTIL BECOMING COMPLETELY
ABSORBED.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  02/0900Z 34.5N  38.1W   55 KT  65 MPH
 12H  02/1800Z 34.3N  37.1W   50 KT  60 MPH
 24H  03/0600Z 34.7N  35.2W   50 KT  60 MPH
 36H  03/1800Z 35.9N  32.6W   45 KT  50 MPH
 48H  04/0600Z 38.8N  30.0W   40 KT  45 MPH
 72H  05/0600Z 45.5N  26.5W   40 KT  45 MPH...POST-TROPICAL
 96H  06/0600Z 49.0N  30.0W   40 KT  45 MPH...POST-TROP/EXTRATROP
120H  07/0600Z...ABSORBED BY LARGER EXTRATROPICAL LOW
 
$$
FORECASTER PASCH