849 
 WTNT43 KNHC 190837
 TCDAT3
 TROPICAL STORM RITA DISCUSSION NUMBER   6
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
 5 AM EDT MON SEP 19 2005
  
 THE NEW RECONAISSANCE AIRCRAFT IN THE SYSTEM AT 07Z FOUND THAT THE
 PRESSURE HAD FALLEN TO 999 MB...AND FIRST SATELLITE IMAGES AFTER
 THE ECLIPSE SHOW THAT CONVECTION IS NOW WRAPPING AROUND TO THE
 NORTHWEST OF THE CENTER AND HAS TAKEN A MORE BANDED APPEARANCE.  A
 DROPSONDE IN THE NORTHWEST QUADRANT HAD 44 KT AT THE SURFACE...WITH
 FLIGHT LEVEL WINDS IN THIS QUADRANT OF 57 KT.  THE NORTHEAST
 QUADRANT HAS NOT YET BEEN SAMPLED...AND I PRESUME THAT HIGHER WINDS
 WILL BE FOUND THERE DURING THE NEXT HOUR OR SO.  THE INITIAL
 INTENSITY IS INCREASED TO 50 KT.
 
 THE LAST TWO AIRCRAFT FIXES INDICATE AN ALMOST DUE WEST MOTION...BUT
 WITH ALL THE CENTER REFORMATIONS THAT HAVE OCCURRED IT IS DIFFICULT
 TO ASCERTAIN A REPRESENTATIVE MOTION.  MY BEST JUDGEMENT IS 280/8. 
 RITA HAS ALREADY PASSED THE LONGITUDE OF THE BREAK IN THE
 SUBTROPICAL RIDGE...AND WILL COME UNDER INCREASING PRESSURE TO HAVE
 THE TRACK NUDGE TO THE LEFT.  FURTHERMORE...NOW THAT THE CONVECTION
 IS BECOMING A LITTLE MORE SYMMETRIC...THERE SHOULD BE LESS
 LIKELIHOOD OF ADDITIONAL NORTHWARD REFORMATIONS OF THE CENTER. 
 MODEL GUIDANCE ADJUSTED TO THE CURRENT LOCATION IS VERY TIGHTLY
 CLUSTERED ON A PATH THROUGH THE FLORIDA STRAITS SOUTH OF KEY
 WEST...AND I HAVE ADJUSTED THE OFFICIAL FORECAST SLIGHTLY SOUTH OF
 THE PREVIOUS ADVISORY.  THERE HAS BEEN A FAIRLY SIGNIFICANT SHIFT
 IN THE GUIDANCE LATE IN THE FORECAST PERIOD...WITH THE GLOBAL
 MODELS ABRUPTLY WEAKENING THE MID-LEVEL HIGH OVER THE WESTERN GULF
 AND ALLOWING RITA TO BEGIN A SHARPER RECURVATURE TRACK.  WHILE I
 HAVE ADJUSTED THE 120-HR POINT ABOUT 120 NM NORTH OF THE PREVIOUS
 ADVISORY...I AM STILL WELL TO THE LEFT OF MOST OF THE 120-HR
 GUIDANCE.  
 
 WATER VAPOR IMAGERY SHOWS THAT THE UPPER-LEVEL LOW IN THE NORTHWEST
 CARIBBEAN IS SHIFTING EASTWARD...AND AS IT DOES SO THE SOUTHERLY
 SHEAR OVER RITA WILL CONTINUE TO DECREASE.  THIS SHOULD ALLOW FOR A
 FASTER DEVELOPMENT RATE.  THE OFFICIAL FORECAST IS VERY CLOSE TO
 THE SHIPS GUIDANCE.
 
  
 FORECASTER FRANKLIN
  
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      19/0900Z 22.7N  74.3W    50 KT
  12HR VT     19/1800Z 23.1N  76.0W    60 KT
  24HR VT     20/0600Z 23.6N  78.5W    70 KT
  36HR VT     20/1800Z 24.0N  81.2W    80 KT
  48HR VT     21/0600Z 24.2N  84.0W    90 KT
  72HR VT     22/0600Z 24.5N  88.5W   100 KT
  96HR VT     23/0600Z 25.5N  92.5W   100 KT
 120HR VT     24/0600Z 27.5N  96.0W    95 KT
  
  
 $$