624 
 WTNT44 KNHC 300232
 TCDAT4
 TROPICAL STORM ISAAC DISCUSSION NUMBER  10
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL092006
 1100 PM EDT FRI SEP 29 2006
  
 THE SHAPE OF THE CLOUD PATTERN HAS BECOME A LITTLE BETTER ORGANIZED
 AND MORE TYPICAL OF A TROPICAL STORM. I DID NOT MAKE ISAAC A
 HURRICANE BECAUSE THE CONVECTION SURROUNDING THE CENTER IS NOT VERY
 STRONG AT THE TIME OF THIS ADVISORY...BUT I WAS VERY TEMPTED. A
 QUIKSCAT PASS OVER THE CYCLONE SHOWED A FEW VECTORS OF 60 KNOTS
 JUST TO THE NORTH OF THE CENTER. HOWEVER...I AM NOT SURE IF THESE
 VECTOR ARE REPRESENTATIVE OR NOT OF THE INTENSITY OF ISAAC...SINCE
 THERE IS ALWAYS A LOT OF GOOD DEBATE ABOUT THE SUBJECT AMONG THE
 QUIKSCAT EXPERTS. HOWEVER...THESE WINDS ARE ONLY 5 KNOTS ABOVE THE
 DVORAK INTENSITY ESTIMATES...AND I AM NOT GOING TO ARGUE OVER 5
 KNOTS. SO LET'S USE THE VECTORS AND INCREASE THE WINDS TO 60 KNOTS.
 UNANIMOUSLY...ALL INTENSITY MODELS BRING ISAAC TO HURRICANE STATUS
 BEFORE THE SHEAR INCREASES AND THE OCEAN COOLS...AND SO DOES THE
 OFFICIAL FORECAST. ISSAC SHOULD BECOME EXTRATROPICAL IN 3 DAYS AND
 BECOME ABSORBED BY A LARGER FRONTAL SYSTEM IN 5 DAYS OR EARLIER.    
 
 ISAAC IS MOVING TOWARD THE WEST-NORTHWEST ABOUT 7 KNOTS BUT IS
 ALREADY REACHING THE WESTERN PORTION OF THE SUBTROPICAL RIDGE AND
 THE SOUTHERLY FLOW ASSOCIATED WITH A STRONG MID-LATITUDE TROUGH.
 THIS PATTERN SHOULD STEER ISAAC NORTHWARD AND PASS WELL EAST OF
 BERMUDA IN THE NEXT DAY OR TWO. IT SHOULD THEN TURN TO THE
 NORTH-NORTHEAST WITH INCREASING FORWARD SPEED. ISAAC IS EXPECTED TO
 BE AN EXTRATROPICAL STORM WHILE APPROACHING SOUTHEASTERN
 NEWFOUNDLAND IN ABOUT 3 DAYS. THIS IS CONSISTENT WITH TRACK
 GUIDANCE WHICH IN FACT HAS SHIFTED TO THE LEFT A LITTLE BIT...AND
 THE MAIN ENVELOPE IS OVER EXTREME SOUTHEASTERN NEWFOUNDLAND AND
 ADJACENT WATERS.
  
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      30/0300Z 30.1N  57.4W    60 KT
  12HR VT     30/1200Z 30.5N  58.4W    65 KT
  24HR VT     01/0000Z 31.5N  59.7W    65 KT
  36HR VT     01/1200Z 33.5N  61.0W    65 KT
  48HR VT     02/0000Z 36.5N  61.0W    60 KT
  72HR VT     03/0000Z 46.0N  55.0W    55 KT...EXTRATROPICAL
  96HR VT     04/0000Z 51.0N  45.0W    45 KT...EXTRATROPICAL
 120HR VT     05/0000Z...ABSORBED BY A FRONTAL SYSTEM
  
 $$
 FORECASTER AVILA