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TROPICAL STORM JOYCE DISCUSSION NUMBER   2
NATIONAL WEATHER SERVICE MIAMI FL
10 PM EST MON SEP 25 2000
 
TROPICAL DEPRESSION FOURTEEN HAS CONTINUED TO BECOME BETTER
ORGANIZED AND IS NOW TROPICAL STORM JOYCE.  THE INITIAL INTENSITY OF
35 IS BASED ON A SATELLITE INTENSITY ESTIMATE OF 35 KT FROM TAFB AND
THE DEVELOPMENT OF A 10 NM DIAMETER EYE-LIKE FEATURE IN THE CENTER
OF CLOUD SYSTEM.  ALTHOUGH THE CONVECTIVE CLOUD TOPS ARE NOT
PARTICULARLY COLD...NEW CONVECTION HAS DEVELOPED AROUND THE CLOUD
HOLE/EYE-LIKE FEATURE DURING THE PAST 2 HOURS.  BANDING FEATURES
HAVE ALSO IMPROVED...AND NIGHTTIME VISIBLE IMAGERY YIELDS A CLOUD
PATTERN INTENSITY CLOSE TO 45 KT.  OUTFLOW IS CONFINED MAINLY TO THE
EAST AND SOUTH OF THE CENTER.
 
THE INITIAL MOTION IS ABOUT 280/13. THERE IS NO CHANGE TO THE
PREVIOUS FORECAST TRACK OR REASONING...AND THE OFFICAL TRACK IS JUST
AN EXTENSION OF THE PREVIOUS FORECAST.  SATELLITE FIXES HAVE BEEN
FALLING ON THE PREVIOUS FORECAST TRACK AND THE LATEST MODEL GUIDANCE
CONTINUES TO INDICATE A GENERAL WESTWARD TRACK THROUGH THE PERIOD. 
THE ONLY MODELS THAT DIFFER FROM THIS SCENARIO ARE THE
AVN...GFDL...AND VBAR MODELS...WHICH TRACK JOYCE TO THE WEST-
SOUTHWEST AFTER 24 HOURS.  IT IS RARE FOR TROPICAL CYCLONES TO MOVE
SOUTH OF WEST THIS FAR EAST...AND THE RIDGE TO THE NORTH OF JOYCE
WILL LIKELY SHIFT SLOWLY NORTHWARD AS ISAAC MOVES MORE TOWARD THE
NORTHWEST WITH TIME.  THIS SHOULD ALLOW JOYCE TO TRACK AT LEAST A
LITTLE NORTH OF DUE WEST THROUGH THE PERIOD.

THE MAIN QUESTION IS WHAT EFEFCT WILL ANY OUTFLOW FROM ISAAC HAVE 
ON JOYCE.  THERE MAY BE SOME WEAK SUBSIDENCE ON THE SOUTHEAST SIDE
OF ISAAC THAT IS CURRENTLY INHIBITING THE DEVELOPMENT OF COLD-
TOPPED DEEP CONVECTION THAT NORMALLY WOULD BE OCCURING BY THIS TIME. 
HOWEVER...AS ISAAC PULLS FARTHER TO THE NORTH AND THE DISTANCE
BETWEEN THE TWO CYCLONES INCREASES...STRONGER CONVECTION SHOULD
DEVELOP UNLESS THE OUTFLOW FROM ISAAC INCREASES THE SHEAR ON JOYCE. 
DUE TO THIS UNCERTAINTY...THE OFFICIAL FORECAST ONLY TAKES JOYCE TO
MINIMAL CATEGORY 1 HURRICANE INTENSITY IN 72 HOURS...WHICH IS 10 KT
BELOW THE SHIPS INTENSITY MODEL FORECAST.
 
FORECASTER STEWART
  
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     26/0300Z 11.7N  32.6W    35 KTS
12HR VT     26/1200Z 12.0N  34.6W    40 KTS
24HR VT     27/0000Z 12.5N  37.2W    45 KTS
36HR VT     27/1200Z 12.8N  39.8W    50 KTS
48HR VT     28/0000Z 13.0N  42.5W    55 KTS
72HR VT     29/0000Z 13.3N  47.9W    65 KTS
  
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