065 
 WTNT44 KNHC 280255
 TCDAT4
  
 TROPICAL STORM ISAAC DISCUSSION NUMBER  28
 NWS NATIONAL HURRICANE CENTER MIAMI FL       AL092012
 1000 PM CDT MON AUG 27 2012
  
 THE SATELLITE PRESENTATION OF ISAAC HAS NOT CHANGED VERY MUCH DURING
 THE PAST FEW HOURS.  INFRARED AND MICROWAVE IMAGERY SHOW A STRONG
 BAND OF CONVECTION...PERHAPS THE BEGINNING OF AN EYEWALL...WRAPPING
 AROUND THE SOUTH AND EAST PORTIONS OF THE CIRCULATION.  HOWEVER...
 AIRCRAFT OBSERVATIONS INDICATE THAT THE CONVECTIVE BAND WAS OPEN TO
 THE NORTHWEST AND THAT THE LOW-LEVEL CENTER WAS DISPLACED A LITTLE
 TO THE SOUTH OF THE ROTATION SEEN IN SATELLITE PICTURES.  THE
 MINIMUM PRESSURE HAS NOT FALLEN SIGNIFICANTLY DURING THE PAST
 SEVERAL HOURS AND THE NOAA AND AIR FORCE AIRCRAFT HAVE NOT REPORTED
 WINDS ANY HIGHER THAN WHAT WAS MEASURED LATE THIS AFTERNOON.
 THEREFORE...ISAAC REMAINS A 60-KT TROPICAL STORM FOR THIS ADVISORY.
 ISAAC CONTINUES TO HAVE DIFFICULTLY MAINTAINING DEEP CONVECTION
 OVER THE NORTHERN SEMICIRCLE LIKELY DUE TO SOME DRY AIR
 ENTRAINMENT.  OTHERWISE...ENVIRONMENTAL CONDITIONS SHOULD BE
 CONDUCIVE FOR STRENGTHENING UNTIL LANDFALL.  ISAAC IS FORECAST TO
 BECOME A HURRICANE OVERNIGHT AND NHC INTENSITY FORECAST IS SLIGHTLY
 HIGHER THAN MOST OF THE GUIDANCE.
  
 ISAAC HAS BEEN MOVING NORTHWESTWARD OR 310 DEGREES AT 9 KT.  THE
 TRACK GUIDANCE HAS CONTINUED TO COME INTO BETTER AGREEMENT DURING
 THE FIRST 36 TO 48 HOURS OF THE FORECAST PERIOD.  ISAAC SHOULD MOVE
 NORTHWESTWARD TOWARD THE NORTH-CENTRAL GULF COAST WHERE A BREAK IN
 THE SUBTROPICAL RIDGE IS LOCATED.  AS A MID-LATITUDE TROUGH
 BYPASSES ISAAC IN A DAY OR SO...SOME RIDGING BUILDS TO THE
 NORTHWEST OF THE CYCLONE.  THIS IS EXPECTED TO CAUSE ISAAC TO
 SLOW DOWN AS IT MOVES INLAND.  AFTER 72 HOURS...THE CYCLONE SHOULD
 BEGIN TO MOVE A LITTLE FASTER TOWARD THE NORTH AND NORTHEAST AS IT
 MOVES AROUND THE WESTERN SIDE OF A MID-LEVEL RIDGE THAT SLIDES
 EASTWARD ACROSS THE OHIO VALLEY AND MID-ATLANTIC REGIONS.  THE NEW
 NHC TRACK IS SIMILAR TO THE PREVIOUS ADVISORY AND REMAINS BETWEEN
 THE ECMWF AND GFS MODELS.
  
 ISAAC IS A LARGE TROPICAL CYCLONE.  A DANGEROUS STORM SURGE...HEAVY
 RAINFALL...AND STRONG WINDS EXTEND WELL AWAY FROM THE CENTER AND
 ARE EXPECTED TO AFFECT A LARGE PORTION OF THE NORTHERN GULF COAST.
 THE THREAT OF HEAVY RAINFALL AND FLOODING IS ALSO EXPECTED TO
 SPREAD INLAND OVER THE LOWER MISSISSIPPI VALLEY REGION DURING THE
 NEXT FEW DAYS.
   
  
 FORECAST POSITIONS AND MAX WINDS
  
 INIT  28/0300Z 27.1N  87.0W   60 KT  70 MPH
  12H  28/1200Z 28.0N  88.0W   70 KT  80 MPH
  24H  29/0000Z 29.1N  89.2W   80 KT  90 MPH...ON THE COAST
  36H  29/1200Z 29.9N  90.1W   65 KT  75 MPH...INLAND
  48H  30/0000Z 30.7N  90.7W   50 KT  60 MPH...INLAND
  72H  31/0000Z 33.3N  91.7W   30 KT  35 MPH...INLAND
  96H  01/0000Z 37.5N  91.5W   25 KT  30 MPH...POST-TROP/REMNT LOW
 120H  02/0000Z 40.5N  87.5W   20 KT  25 MPH...POST-TROP/REMNT LOW
  
 $$
 FORECASTER BROWN/BLAKE