778 
 WTNT44 KNHC 152051
 TCDAT4
 HURRICANE IVAN DISCUSSION NUMBER  54
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
 5 PM EDT WED SEP 15 2004
  
 SATELLITE IMAGERY THIS AFTERNOON SHOWS AN EXPANSION OF COLD EYEWALL
 CONVECTION...ESPECIALLY ON THE WEST SIDE...AND A CLEARING OUT OF
 THE EYE. THE AIR FORCE HURRICANE HUNTER AIRCRAFT REPORTED AN
 CENTRAL PRESSURE OF 933 MB...AND THE NOAA AIRCRAFT REPORTED PEAK
 WINDS AT 7000 FT OF 132 KT.  UNDERNEATH THAT FLIGHT-LEVEL WIND THE
 STEPPED FREQUENCY MICROWAVE RADIOMETER REPORTED 108 KT.  IT APPEARS
 THAT IVAN IS BEGINNING TO RESPOND TO THE WARM POOL OVER WHICH IT
 HAS BEEN TRAVERSING TODAY. THE MAXIMUM WINDS HAVE NOT YET INCREASED
 BUT MAY DO SO OVER THE NEXT FEW HOURS. HOWEVER...SLIGHTLY COOLER
 WATERS EXIST JUST OFFSHORE...AND LITTLE NET CHANGE IN STRENGTH IS
 EXPECTED PRIOR TO LANDFALL.
 
 IVAN REMAINS BASICALLY ON TRACK...WITH AN INITIAL MOTION ESTIMATED
 AT 355/12. THERE HAS BEEN ESSENTIALLY NO CHANGE TO THE TRACK
 FORECAST...WITH LANDFALL EXPECTED IN ABOUT 9 HOURS.  HOWEVER...IVAN
 HAS A VERY LARGE WINDFIELD AND DAMAGING WINDS WILL MOVE ONSHORE
 MUCH SOONER THAN THAT.  THE ECMWF MODEL FINALLY GAVE UP ON A NEW
 ORLEANS LANDFALL TODAY...RESULTING IN A WELL-CLUSTERED GUIDANCE
 ENVELOPE UNTIL WELL AFTER LANDFALL...WHERE THERE ARE A VARIETY OF
 POSSIBLE SOLUTIONS FOR THE REMNANTS OF IVAN.  THE OFFICIAL FORECAST
 CONTINUES TO SHOW THE POSSIBILITY OF A MAJOR FLOODING EVENT OVER
 THE SOUTHERN APPALACHIANS LATE IN THE FORECAST PERIOD.
 
 THE LARGE CIRCULATION OF IVAN CAN BE EXPECTED TO BRING HURRICANE
 FORCE WINDS WELL INLAND...PERHAPS 150 MILES OR SO.
  
 FORECASTER FRANKLIN
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      15/2100Z 28.4N  88.3W   115 KT
  12HR VT     16/0600Z 30.2N  88.3W   115 KT...ON THE COASTLINE
  24HR VT     16/1800Z 32.2N  88.0W    65 KT...INLAND
  36HR VT     17/0600Z 33.8N  87.2W    35 KT...INLAND
  48HR VT     17/1800Z 35.0N  86.0W    25 KT...INLAND
  72HR VT     18/1800Z 36.0N  84.0W    20 KT...INLAND
  96HR VT     19/1800Z 36.0N  84.0W    20 KT...DISSIPATING
 120HR VT     20/1800Z...DISSIPATED
  
  
 $$