HOME	ARCHIVES	FORECASTS	IMAGERY	ABOUT TPC	RECONNAISSANCE

ZCZC MIATCDAT5 ALL
TTAA00 KNHC DDHHMM
TROPICAL STORM ISIDORE DISCUSSION NUMBER  36
NATIONAL WEATHER SERVICE MIAMI FL
11 PM EDT TUE SEP 24 2002

THUS FAR...THERE HAS BEEN NO EVIDENCE THAT ISIDORE IS REDEVELOPING
AN INNER CORE...I.E.  STRONG CENTRAL CONVECTION AND A SMALL RADIUS
OF MAXIMUM WINDS.  IN FACT...SURFACE OBSERVATIONS...DATA FROM THE
AIR FORCE RESERVES...AND THE NOAA G-IV JET SHOW THAT THE STRONGEST
WINDS ARE LOCATED SOME 120 N MI OR MORE TO THE NORTHEAST OF THE
CENTER.  SIGNIFICANT STRENGTHENING IS NOT LIKELY UNTIL THE INNER
CORE IS RE-ESTABLISHED.  AS THE CYCLONE MOVES FARTHER NORTH AND AWAY
FROM THE SHELF WATERS NORTH OF YUCATAN...IT SHOULD ENCOUNTER A
FAIRLY DEEP LAYER OF WARM WATER...HIGH HEAT CONTENT...WHICH WOULD
FAVOR STRENGTHENING.  ALTHOUGH THE UPPER-LEVEL ENVIRONMENT HAS
LOOKED QUITE FAVORABLE FOR STRENGTHENING...WATER VAPOR IMAGERY NOW
SHOWS A WEAK UPPER-LEVEL TROUGH IMPINGING ON THE NORTHWEST PART OF
THE STORM CIRCULATION.  OBSERVATIONS FROM THE NOAA JET INDICATED DRY
AIR IN THE AREA...PROBABLY ASSOCIATED WITH THE TROUGH.  THIS MAY BE
AN INHIBITING FACTOR.  THE OFFICIAL FORECAST STILL ALLOWS FOR THE
SYSTEM TO REACH HURRICANE INTENSITY BEFORE LANDFALL.

THERE IS LITTLE CHANGE TO THE TRACK FORECAST AND REASONING FROM THE 
PREVIOUS ADVISORY.  WITH A MID-TROPOSPHERIC RIDGE TO ITS EAST AND A 
BROAD MID-LATITUDE TROUGH TO ITS NORTHWEST...ISIDORE IS EXPECTED TO 
CONTINUE TO BE STEERED IN A GENERALLY NORTHWARD DIRECTION UNTIL 
LANDFALL.  THIS IN GOOD AGREEMENT WITH THE TRACK GUIDANCE 
MODELS...WHICH THEMSELVES ARE IN GOOD AGREEMENT.  ONLY A SLIGHT 
INCREASE IN FORWARD SPEED IS EXPECTED... UNTIL AFTER LANDFALL.  
THEN...ISIDORE...OR ITS EXTRATROPICAL REMNANT...SHOULD ACCELERATE 
NORTHEASTWARD UNDER THE INFLUENCE OF THE MID-LATITUDE TROUGH.
 
FORECASTER PASCH
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     25/0300Z 23.5N  89.7W    50 KTS
12HR VT     25/1200Z 25.0N  90.0W    55 KTS
24HR VT     26/0000Z 27.2N  90.2W    65 KTS
36HR VT     26/1200Z 29.7N  90.2W    60 KTS...INLAND
48HR VT     27/0000Z 33.0N  89.0W    30 KTS...INLAND
72HR VT     28/0000Z 41.0N  76.0W    25 KTS...EXTRATROPICAL
 
NNNN