[Tropical] Tropical Cyclone Discussion

[EMWIN Server]

WTNT42 KNHC 210830
TCDAT2
HURRICANE KARL DISCUSSION NUMBER  19
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
5 AM EDT TUE SEP 21 2004

DVORAK T-NUMBERS AT AROUND 06Z WERE 6.5 FROM TAFB AND SAB AND 6.0
FROM AFWA...CORRESPONDING TO INTENSITY ESTIMATES OF 127 KT AND 115
KT RESPECTIVELY.  MORE RECENTLY...THERE HAS BEEN SOME EROSION OF
THE COLD CLOUD TOPS SURROUNDING THE EYE OVER THE NORTHERN
SEMICIRCLE.  CURRENT INTENSITY IS KEPT AT 120 KT.  KARL MAY HAVE
ALREADY REACHED ITS MAXIMUM STRENGTH.  NO SIGNIFICANT CHANGES IN
INTENSITY ARE ANTICIPATED UNTIL THE HURRICANE REACHES SLIGHTLY
COOLER WATERS AND SOUTHWESTERLY SHEAR INCREASES...I.E. IN ABOUT 48
HOURS.  BY DAY 4 KARL SHOULD BE PASSING OVER MUCH COOLER WATERS AND
LOSING TROPICAL CHARACTERISTICS.  THE INTENSITY FORECAST IS IN
REASONABLE AGREEMENT WITH THE LATEST SHIPS GUIDANCE...ALTHOUGH HELD
UP A LITTLE HIGHER LATE IN THE PERIOD SINCE THE CYCLONE MAY DERIVE
SOME ENERGY FROM BAROCLINIC SOURCES.

KARL HAS TURNED TO THE RIGHT...TOWARD A WEAKNESS IN THE SUBTROPICAL
RIDGE.  INITIAL MOTION IS NOW ESTIMATED TO BE 340/10.  TRACK
GUIDANCE IS IN FAIRLY GOOD AGREEMENT ABOUT A TURN TO THE NORTH IN
ROUGHLY 24 HOURS...TOWARD THE NORTH-NORTHEAST BY 48-72 HOURS...AND
THEN BACK TO THE NORTH LATER IN THE PERIOD AS KARL BEGINS TO MOVE
AROUND A LARGE DEEP-LAYER CYCLONE AT HIGHER LATITUDES.  THERE ARE
HOWEVER SOME SIGNIFICANT DIFFERENCES IN THE FORWARD SPEED PREDICTED
BY THE MODELS. THE CURRENT OFFICIAL FORECAST IS A LITTLE TO THE
EAST AND SLIGHTLY SLOWER THAN THE PREVIOUS ONE...ALBEIT FASTER THAN
THE DYNAMICAL MODEL CONSENSUS.

FORECASTER PASCH

FORECAST POSITIONS AND MAX WINDS

INITIAL      21/0900Z 20.1N  47.5W   120 KT
 12HR VT     21/1800Z 21.7N  48.4W   120 KT
 24HR VT     22/0600Z 23.9N  49.5W   120 KT
 36HR VT     22/1800Z 26.5N  49.5W   120 KT
 48HR VT     23/0600Z 29.2N  47.8W   115 KT
 72HR VT     24/0600Z 36.0N  43.5W    95 KT
 96HR VT     25/0600Z 44.0N  43.5W    75 KT...EXTRATROPICAL
120HR VT     26/0600Z 48.0N  44.0W    60 KT...EXTRATROPICAL

$$This weather bulletin was brought to you by:
www.nashvilleweather.net