[Tropical] Tropical Cyclone Discussion

[EMWIN Server]

WTNT43 KNHC 231503
TCDAT3
TROPICAL STORM LISA DISCUSSION NUMBER  17
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
11 AM EDT THU SEP 23 2004

EARLY VISIBLE SATELLITE IMAGERY SHOWS THAT LISA IS A LITTLE
DISORGANIZED WITH UPPER LEVEL WINDS FROM THE NORTH CAUSING VERTICAL
SHEAR.  ALSO THERE IS STILL A HINT OF TWO POORLY DEFINED CENTERS.
THIS ADVISORY IS FOLLOWING THE CENTER TO THE SOUTHWEST WHICH
APPEARS TO BE THE DOMINANT ONE.  THE SHIPS MODEL INDICATES VERY
LITTLE VERTICAL SHEAR AFTER 36 HOURS AND BRINGS LISA TO A HURRICANE
IN 72 HOURS.  THE  OFFICIAL FORECAST IS IN AGREEMENT WITH THIS
GUIDANCE.

THE MOTION HAS BEEN SLOW AND GENERALLY SOUTHWESTWARD UNDER WEAK
STEERING CURRENTS.  THE FORECAST IS FOR A TURN TOWARD THE
NORTH-NORTHWEST IN A DAY OR SO TOWARD A WEAKNESS IN THE SUBTROPICAL
RIDGE.  THE GLOBAL MODELS ARE IN GOOD AGREEMENT ABOUT THIS SCENARIO
WITH SOME EAST-WEST SPREAD AFTER 72 HOURS.  THE OFFICIAL TRACK
FORECAST IS IN CLOSE AGREEMENT WITH A CONSENSUS OF THE GLOBAL
MODELS EXCEPT AT 12 AND 24 WHEN IT IS LEFT OF THE CONSENSUS SINCE
THE INITIAL MOTION IS GIVEN MORE WEIGHT.

FORECASTER LAWRENCE

FORECAST POSITIONS AND MAX WINDS

INITIAL      23/1500Z 12.1N  41.7W    40 KT
 12HR VT     24/0000Z 12.1N  42.0W    45 KT
 24HR VT     24/1200Z 12.3N  42.7W    45 KT
 36HR VT     25/0000Z 13.2N  43.2W    50 KT
 48HR VT     25/1200Z 14.5N  43.8W    55 KT
 72HR VT     26/1200Z 17.5N  45.0W    65 KT
 96HR VT     27/1200Z 21.5N  46.0W    65 KT
120HR VT     28/1200Z 24.5N  46.5W    65 KT


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