603 
 WTNT41 KNHC 160836
 TCDAT1
 TROPICAL STORM OPHELIA DISCUSSION NUMBER  41
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
 5 AM EDT FRI SEP 16 2005
  
 SATELLITE...RADAR...AND RECONAISSANCE DATA INDICATE THAT OPHELIA
 CONTINUES TO LOSE ORGANIZATION...WITH THE MID-LEVEL CIRCULATION
 VISIBLE ON RADAR LOCATED TO THE EAST OF THE LOW-LEVEL CENTER
 DETERMINED BY AIRCRAFT AND DROPSONDES.  FIRST SATELLITE IMAGES
 AFTER THE ECLIPSE SHOW THAT THE DEEP CONVECTION IS RESTRICTED TO
 THE EASTERN QUADRANT.  THE INITIAL INTENSITY OF 55 KT IS BASED ON
 850 MB FLIGHT LEVEL WINDS OF 71 KT...AND DROPSONDES REPORTING
 SURFACE WINDS IN THE 50-55 KT RANGE.
 
 OPHELIA IS SOUTH OF A WEAK 500 MB RIDGE IN THE WESTERLIES...WHICH
 ALONG WITH MID-LEVEL HIGH PRESSURE OVER BERMUDA...HAS BEEN IMPEDING
 THE MOTION OF THE CYCLONE AWAY FROM THE NORTH CAROLINA COAST. THE
 NEXT UPSTREAM TROUGH IS CURRENTLY OVER ILLINOIS. AS THIS TROUGH
 PROGRESSES EASTWARD OVER THE NEXT 24 HOURS...OPHELIA IS EXPECTED TO
 TURN NORTHEASTWARD AND ACCELERATE. MOST OF THE GLOBAL MODELS KEEP
 THE BERMUDA HIGH IN PLACE LONG ENOUGH TO FORCE OPHELIA ON A PATH
 CLOSE TO SOUTHERN NEW ENGLAND AND THE CANDIAN MARITIMES. MODEL
 GUIDANCE IS IN EXCELLENT AGREEMENT ON THE TRACK BUT WITH SOME
 DIFFERENCES IN SPEED.  THE OFFICIAL FORECAST IS VERY CLOSE TO THE
 PREVIOUS ADVISORY AND THE DYNAMICAL MODEL CONSENSUS.  HOWEVER...THE
 TILT OF THE VORTEX INDICATES THAT SHEAR IS BEGINNING TO AFFECT THE
 STORM STRUCTURE...AND SHOULD OPHELIA SHEAR OFF IT WOULD PROBABLY
 NOT ACCELERATE AS RAPIDLY AS FORECAST.  ASSUMING THE TRACK IS
 ROUGHLY CORRECT...OPHELIA WILL BE OVER 20C WATER IN 36 HOURS AND
 WOULD LIKELY BE EXTRATROPICAL SHORTLY THEREAFTER.
 
 THE PRESSURE HAS RISEN MARKEDLY THIS EVENING BUT THERE HAS BEEN ONLY
 A MODEST DECREASE IN THE WINDS.  ALL THE OBJECTIVE INTENSITY
 GUIDANCE SHOWS ONLY A SLIGHT ADDITIONAL DECREASE IN INTENSITY. 
 AGAIN...SHOULD OPHELIA BECOME SHEARED IT WOULD LIKELY WEAKEN MORE
 RAPIDLY.
  
 FORECASTER FRANKLIN
  
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      16/0900Z 35.1N  74.8W    55 KT
  12HR VT     16/1800Z 36.1N  74.0W    55 KT
  24HR VT     17/0600Z 38.0N  72.0W    55 KT
  36HR VT     17/1800Z 41.0N  69.0W    55 KT
  48HR VT     18/0600Z 44.0N  64.0W    50 KT...EXTRATROPICAL
  72HR VT     19/0600Z 48.5N  51.0W    50 KT...EXTRATROPICAL
  96HR VT     20/0600Z 52.0N  36.0W    45 KT...EXTRATROPICAL
 120HR VT     21/0600Z 54.0N  21.0W    45 KT...EXTRATROPICAL
  
  
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