084 
 WTNT43 KNHC 210311
 TCDAT3
 HURRICANE RITA DISCUSSION NUMBER  14
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
 11 PM EDT TUE SEP 20 2005
  
 DATA FROM AN AIR FORCE RESERVE UNIT RECON AIRCRAFT AT 21/0020Z IN
 THE NORTHEAST QUADRANT INDICATED 700 MB FLIGHT-LEVEL WINDS OF 103
 KT...ROUGHLY 93 KT SURFACE WINDS. DOPPLER RADAR VELOCITIES FROM KEY
 WEST HAVE BEEN AS HIGH AS 113 KT AT 9500 FEET IN SPOTS...WITH THE
 MAJORITY OF THE HIGHEST VALUES IN THE 105-107 KT RANGE...WHICH
 EQUALS ABOUT 95 KT SURFACE WINDS. A RECON PASS THROUGH THE 28 NMI
 DIAMETER EYE AT 0204Z INDICATED A SURFACE PRESSURE OF 965 MB...
 WHICH ROUGHLY EQUALS 95 KT. THEREFORE...THE INITIAL INTENSITY HAS
 BEEN INCREASED TO 95 KT...OR JUST BELOW MAJOR HURRICANE STRENGTH.
  
 THE INITIAL MOTION IS 275/11. RITA IS EXPECTED TO CONTINUE MOVING A
 LITTLE NORTH OF DUE WEST FOR THE NEXT 36-48 HOURS AS THE STRONG
 RIDGE TO THE NORTH REMAINS INTACT ALONG THE GULF COAST AND INTO
 CENTRAL AND NORTHERN TEXAS. THE 18Z GFS AND GFS-ENSEMBLE MODELS
 HAVE SHIFTED EASTWARD TO NEAR THE TEXAS-LOUISIANA BORDER. HOWEVER
 ...BOTH MODELS WERE FORECASTING THE 21/00Z 500 MB HEIGHTS ACROSS
 TEXAS TO DECREASE BY 20 METERS...WHEN IN FACT... 21/00Z UPPER-AIR
 DATA INDICATE THE HEIGHTS DID NOT CHANGE AND THE MID-LEVEL HIGH
 OVER NORTHWEST TEXAS HAS REMAINED QUITE STRONG WITH HEIGHTS NEAR
 6000 METERS. AS A RESULT...LESS WEIGHT WAS PALCED ON THE GFS MODEL
 ...SINCE IT APPEARS TO BE DECREASING THE STRENGTH OF THE RIDGE TOO
 QUICKLY...THE OFFICIAL FORECAST TRACK IS JUST AN UPDATE AND
 EXTENSION OF THE PREVIOUS ADVISORY TRACK...AND IS CLOSE TO THE NHC
 MODEL CONSENSUS.
  
 THE PREVIOUS ADVISORY INDICATING RAPID INTENSIFICATION FOR THE NEXT
 24 HOURS APPEARS TO BE ON TRACK. DURING THE PAST 14 HOURS...THE
 CENTRAL PRESSURE HAS DECREASED 20 MB...OR AT A RATE OF ABOUT 2
 DVORAK T-NUMBERS PER 24 HOURS. WHILE SUCH A LARGE PRESSURE FALL
 TREND RARELY OCCURS FOR MORE THAN 24 HOURS...THE VERY FAVORABLE
 UPPER-LEVEL OUTFLOW PATTERN AND 30C-31C SSTS BENEATH RITA SUGGEST
 THAT RAPID INTENSIFICATION SHOULD CONTINUE FOR AT LEAST ANOTHER 24
 HOURS. A POLEWARD OUTFLOW CHANNEL IS WELL ESTABLISHED WITH OUTFLOW
 ACCUMULATING INTO A LARGE UPPER-LEVEL LOW...OR MASS SINK...EAST OF
 THE BAHAMAS. IN ADDITION... AN EQUATORWARD OUTFLOW CHANNEL ALSO
 APPEARS TO BE DEVELOPING. GIVEN THE DUAL OUTFLOW PATTERN THAT IS
 EXPECTED TO PERSIST FOR THE NEXT 36-48 HOURS...STRENGTHENING INTO A
 CATEGORY 5 HURRICANE IS A DISTINCT POSSIBILITY. BY 72 HOURS... A
 GRADUAL INCREASE IN THE SOUTHWESTERLY VERTICAL SHEAR IS EXPECTED TO
 BRING ABOUT SOME WEAKENING. HOWEVER...THE GFS-BASED SHIPS MODEL
 THAT IS INDICATING 25-30 KT OF SHEAR MAY BE INCLUDING THE WINDS
 ASSOCIATED WITH THE STRONG OUTFLOW PATTERN DEPICTED BY THE MODEL.
 THIS WOULD MEAN THAT THE GFS SHEAR IS TOO HIGH...AND THUS...THE
 SHARP GFS WEAKENING OF RITA DOWN TO 99 KT AT LANDFALL WOULD BE
 PREMATURE. THE OFFICIAL INTENSITY FORECAST LEANS CLOSER TO THE FSU
 SUPERENSEMBLE INTENSITY FORECAST OF 122 KT IN 48 HOURS AND 126 KT
 IN 60 HOURS.
  
 FORECASTER STEWART
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      21/0300Z 24.1N  83.2W    95 KT
  12HR VT     21/1200Z 24.2N  85.2W   105 KT
  24HR VT     22/0000Z 24.4N  87.5W   120 KT
  36HR VT     22/1200Z 24.6N  89.4W   125 KT
  48HR VT     23/0000Z 25.1N  91.4W   125 KT
  72HR VT     24/0000Z 27.1N  94.7W   120 KT
  96HR VT     25/0000Z 30.5N  96.5W    60 KT...INLAND
 120HR VT     26/0000Z 34.5N  96.5W    25 KT...DISSIPATING INLAND
  
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