760 
 WTNT44 KNHC 301443
 TCDAT4
  
 HURRICANE NADINE DISCUSSION NUMBER  72
 NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142012
 1100 AM AST SUN SEP 30 2012
  
 THE EYE OF NADINE HAS BECOME A LITTLE SMALLER AND BETTER DEFINED
 THIS MORNING...HOWEVER THE CONVECTIVE CLOUD TOPS HAVE WARMED
 SOMEWHAT.  THIS RESULTS IN LITTLE CHANGE TO THE MOST RECENT
 SUBJECTIVE AND OBJECTIVE DVORAK T-NUMBERS...AND A CONSENSUS OF
 THE LATEST SATELLITE-BASED INTENSITY ESTIMATES SUPPORT AN INITIAL
 INTENSITY OF 80 KT.  THE HURRICANE IS EXPECTED TO REMAIN IN A
 LOW-SHEAR ENVIRONMENT DURING THE NEXT COUPLE OF DAYS.  SINCE NADINE
 IS FORECAST TO SLOW DOWN AND NOT MOVE VERY FAR...THERE COULD BE
 SOME UPWELLING WHICH WILL CAUSE THE ALREADY MARGINAL SSTS TO COOL.
 AT THE SAME TIME...THE UPPER ATMOSPHERE IS FORECAST TO COOL WHICH
 COULD OFFSET THE COOLER WATER.  THEREFORE...LITTLE CHANGE IN
 INTENSITY IS PREDICTED DURING THE NEXT COUPLE OF DAYS.  AFTER 48
 HOURS...INCREASING WESTERLY SHEAR AND PROGRESSIVELY COOLER WATER
 ALONG THE PATH OF THE STORM SHOULD CAUSE WEAKENING...AND NADINE
 IS PREDICTED TO BECOME POST-TROPICAL BY THE END OF THE PERIOD.
  
 NADINE HAS BEEN MOVING STEADILY NORTHWESTWARD DURING THE PAST 12-18
 HOURS...HOWEVER THE HURRICANE SHOULD SLOW DOWN CONSIDERABLY LATER
 TODAY AS THE STEERING CURRENTS WEAKEN ONCE AGAIN.  NADINE IS
 FORECAST TO COMPLETE A COUNTERCLOCKWISE LOOP DURING THE NEXT COUPLE
 OF DAYS AS IT REMAINS BETWEEN MID-LEVEL RIDGES TO ITS EAST AND
 WEST AND A BROAD TROUGH OVER THE NORTH-CENTRAL ATLANTIC. AFTER 48
 HOURS...A LARGE DEEP-LAYER TROUGH IS FORECAST TO MOVE OFF THE
 COAST OF CANADA.  THIS TROUGH IS EXPECTED TO DEEPEN AND CUT OFF
 AS IT MOVES INTO THE CENTRAL ATLANTIC IN 4-5 DAYS.  THIS SYSTEM
 SHOULD FINALLY CAUSE NADINE TO ACCELERATE NORTHEASTWARD...HOWEVER
 THERE IS SOME DISAGREEMENT IN THE MODELS NEAR THE END OF THE PERIOD
 AS TO WHETHER NADINE CONTINUES NORTHEASTWARD OVER THE NORTHEAST
 ATLANTIC OR TURNS WESTWARD AND IS ABSORBED BY THE UPPER-LOW.  THE
 NHC FORECAST SPLITS THESE DIFFERENCES AND IS NEAR THE DYNAMICAL
 MODEL CONSENSUS AND THE GFS ENSEMBLE MEAN. 
  
 FORECAST POSITIONS AND MAX WINDS
  
 INIT  30/1500Z 37.1N  38.6W   80 KT  90 MPH
  12H  01/0000Z 37.3N  39.1W   80 KT  90 MPH
  24H  01/1200Z 36.6N  39.3W   75 KT  85 MPH
  36H  02/0000Z 35.9N  39.0W   70 KT  80 MPH
  48H  02/1200Z 35.6N  38.1W   65 KT  75 MPH
  72H  03/1200Z 36.3N  35.1W   60 KT  70 MPH
  96H  04/1200Z 40.8N  30.0W   55 KT  65 MPH
 120H  05/1200Z 48.0N  28.0W   45 KT  50 MPH...POST-TROP/EXTRATROP
  
 $$
 FORECASTER BROWN