Tropical Storm CELIA

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TROPICAL STORM CELIA DISCUSSION NUMBER   9
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
8 PM PDT TUE JUL 20 2004
 
CELIA HAS FLUCTUATED IN ORGANIZATION DURING THE EVENING.  THE
CENTRAL CONVECTION IS A LITTLE MORE CONCENTRATED THAN EARLIER...AND
A SHORT-LIVED EYE-WANNABE APPEARED IN THE CONVECTION.  HOWEVER...
OVERALL THE AMOUNT AND INTENSITY OF THE CONVECTION HAS DECREASED. 
SATELLITE INTENSITY ESTIMATES ARE 55 KT FROM TAFB...AND 45 KT FROM
SAB AND AFWA.  THE INITIAL INTENSITY REMAINS 45 KT.

THE STORM HAS JOGGED A LITTLE TO THE RIGHT DURING THE PAST 6 HR...
POSSIBLY DUE TO A REFORMATION OF THE CENTER.  THE BEST ESTIMATE OF
THE INITIAL MOTION IS 295/7.  CELIA IS SOUTH OF A WEAKNESS IN THE
SUBTROPICAL MID LEVEL RIDGE...WHICH LARGE-SCALE MODELS FORECAST TO
PERSIST.  MODEL GUIDANCE IS SOMEWHAT SPREAD BETWEEN WEST-
NORTHWESTWARD AND WESTWARD MOTIONS.  THE MOST SOUTHERLY OF THE
MODELS...THE GFS AND THE UKMET...HAVE A RELATIVELY WEAK
REPRESENTATION OF THE STORM AND ARE QUICKER TO DISSIPATE IT.  THE
GFDL AND THE NOGAPS HAVE A STRONGER REPRESENTATION OF THE CYCLONE
AND A MORE NORTHERLY TRACK.  THE OFFICIAL FORECAST IS IN BEST
AGREEMENT WITH THE GFDL AND THE GUNS CONSENSUS MODEL...CALLING FOR
A WEST-NORTHWESTWARD MOTION FOR ABOUT 72 HR FOLLOWED BY A WESTWARD
TURN AS CELIA WEAKENS OVER COLD WATER.  THE NEW FORECAST IS NUDGED
A LITTLE TO THE NORTH OF THE PREVIOUS FORECAST.

AN UPPER-LEVEL LOW NORTHEAST OF CELIA IS IMPEDING THE OUTFLOW IN
THAT QUADRANT.  OTHERWISE...IT HAS GOOD OUTFLOW.  THE JOG TO THE
RIGHT HAS BROUGHT CELIA CLOSER TO THE EDGE OF THE SEA SURFACE
TEMPERATURE GRADIENT...AND THE FORECAST TRACK TAKES THE CYCLONE
OVER PROGRESSIVELY COOLER WATER.  THERE IS STILL AN OPPORTUNITY FOR
STRENGTHENING FOR 12-24 HR BEFORE CELIA REACHES THE 26C ISOTHERM. 
AFTER THAT...THE CYCLONE SHOULD PROGRESSIVELY WEAKEN.  NOTE THAT
ANY MOTION TO THE RIGHT OF THE FORECAST TRACK WOULD BE INTO EVEN
COLDER WATER AND LIKELY HASTEN THE DEMISE OF THE SYSTEM. 

FORECASTER BEVEN
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      21/0300Z 16.1N 119.0W    45 KT
 12HR VT     21/1200Z 16.6N 120.3W    50 KT
 24HR VT     22/0000Z 17.0N 121.9W    50 KT
 36HR VT     22/1200Z 17.4N 123.5W    45 KT
 48HR VT     23/0000Z 17.8N 125.2W    40 KT
 72HR VT     24/0000Z 18.5N 128.5W    35 KT
 96HR VT     25/0000Z 19.0N 132.0W    30 KT
120HR VT     26/0000Z 19.0N 135.5W    25 KT...DISSIPATING
 
 
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