[Tropical] Tropical Cyclone Discussion

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WTNT43 KNHC 200901
TCDAT3
TROPICAL STORM RITA DISCUSSION NUMBER  10
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
5 AM EDT TUE SEP 20 2005

THE RADAR PRESENTATION OF RITA IS SLOWLY BECOMING BETTER DEFINED...
BUT THE CYCLONE STILL LACKS A CLEAR AND PERSISTENT EYEWALL
SIGNATURE. FLIGHT-LEVEL AND DROPSONDE OBSERVATIONS FROM THE AIR
FORCE RECONAISSANCE AIRCRAFT STILL DO NOT QUITE SUPPORT UPGRADING
RITA TO A HURRICANE. A PEAK 700 MB FLIGHT-LEVEL WIND OF 72 KT WINDS
WOULD CORRESPOND TO 65 KT IN AN EYEWALL...BUT RITA DOES NOT HAVE A
TRUE EYEWALL AND DROPSONDE DATA INDICATE THAT 90 PERCENT IS NOT THE
APPROPRIATE ADJUSTMENT WITH THIS STORM AT THIS TIME. THE INTENSITY
WILL BE HELD AT 60 KT AT THIS TIME.

RITA REMAINS BASICALLY ON TRACK...WITH AN INITIAL MOTION OF 285/13.
LITTLE CHANGE HAS BEEN MADE TO THE OFFICIAL FORECAST IN THE EARLY
GOING...AS RITA MOVES SOUTH OF MID-LEVEL HIGH PRESSURE THROUGH THE
FLORIDA STRAITS.  LATE IN THE FORECAST PERIOD...THE GFS...UKMET...
AND GFDL MODELS HAVE SHIFTED WESTWARD TOWARD THE MIDDLE TEXAS
COAST...WHILE THE NOGAPS IS STILL ON THE SOUTH END OF THE GUIDANCE
ENVELOPE IN EXTREME SOUTH TEXAS.  THE OFFICIAL FORECAST IS ADJUSTED
A LITTLE WESTWARD TOWARD THE DYNAMICAL MODEL CONSENSUS.  AT THIS
POINT IT IS WAY TO EARLY TO SPECIFY WHERE THE GULF LANDFALL MIGHT
OCCUR.

RITA IS STILL EXPECTED TO REACH HURRICANE STRENGTH VERY SOON.  THE
UPPER-LEVEL FLOW PATTERN IS FAVORABLE FOR STRENGTHENING BUT NOT
OVERLY SO...WITH OUTFLOW A LITTLE SQUASHED TO THE NORTH AND
NON-EXISTENT TO THE SOUTH...AND THE UPPER ANTICYCLONE LOCATED WELL
TO THE EAST OF THE CENTER.  EVEN THE RADAR PRESENTATION LOOKS
ELONGATED.  STEADY...BUT NOT EXPLOSIVE DEVELOPMENT IS LIKELY DURING
THE NEXT 12 TO 24 HOURS.  THE UPPER PATTERN COULD IMPROVE SOMEWHAT
IN THE GULF OF MEXICO AND RITA IS STILL FORECAST TO BECOME A MAJOR
HURRICANE.  THE MOST RECENT SHIPS GUIDANCE...HOWEVER...DOES NOT
QUITE GET RITA THERE...AND I WOULD NOT BE SHOCKED IF RITA ENDS UP
FALLING JUST SHORT OF THAT THRESHOLD.

FORECASTER FRANKLIN


FORECAST POSITIONS AND MAX WINDS

INITIAL      20/0900Z 23.7N  79.5W    60 KT
 12HR VT     20/1800Z 24.1N  81.7W    70 KT
 24HR VT     21/0600Z 24.4N  84.4W    80 KT
 36HR VT     21/1800Z 24.6N  87.0W    90 KT
 48HR VT     22/0600Z 24.7N  89.3W    95 KT
 72HR VT     23/0600Z 25.5N  93.0W   100 KT
 96HR VT     24/0600Z 28.5N  96.0W   100 KT
120HR VT     25/0600Z 32.5N  97.5W    35 KT...INLAND


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