[Tropical] Tropical Cyclone Discussion

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WTNT43 KNHC 230832
TCDAT3
TROPICAL STORM LISA DISCUSSION NUMBER  16
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
5 AM EDT THU SEP 23 2004

LISA IS CONTINUING TO MERGE WITH A NEARBY TROPICAL DISTURBANCE.  A
LOW- TO MID-LEVEL TROUGH EXTENDING EASTWARD A FEW HUNDRED MILES
FROM THE ESTIMATED CENTER OF THE STORM IS PROBABLY A REFLECTION OF
THIS DISTURBANCE.  SATELLITE IMAGERY SUGGESTS THAT MOST OF THE DEEP
CONVECTION IN THIS COMBINED SYSTEM IS NOW BEING PRODUCED BY THE
CIRCULATION OF LISA... AND NOT THE DISTURBANCE.  BASED ON DVORAK
CLASSIFICATIONS...THE INTENSITY IS HELD AT 45 KT.  LISA'S
UPPER-LEVEL OUTFLOW IS BEING RESTRICTED BY NORTHERLY UPPER-LEVEL
FLOW FROM THE OUTFLOW OF LARGE AND POWERFUL HURRICANE KARL.  AS
KARL MOVES FARTHER NORTHWARD...ITS INFLUENCE ON LISA WILL DIMINISH.
NOT MUCH CHANGE IN STRENGTH IS LIKELY UNTIL THE SYSTEM BECOMES
BETTER ORGANIZED AND MORE CONSOLIDATED...WHICH IS LIKELY TO HAPPEN
WITHIN A DAY OR SO.

THE ESTIMATED INITIAL MOTION IS A WESTWARD DRIFT.  THERE IS NO
CHANGE TO THE TRACK FORECAST REASONING FROM THE PREVIOUS PACKAGE.
A WEAK RIDGE TO THE NORTH SHOULD STEER LISA SLOWLY WESTWARD TO
WEST-NORTHWESTWARD FOR THE NEXT COUPLE OF DAYS.  THEREAFTER A
MID-TROPOSPHERIC TROUGH IN THE VICINITY OF 50W IS LIKELY TO INDUCE A
TURN TOWARD THE NORTHWEST AND NORTH-NORTHWEST.  THE OFFICIAL
FORECAST IS VERY SIMILAR TO THE PREVIOUS ONE...AND NEAR THE LEFT
SIDE OF THE DYNAMICAL MODEL SUITE.

FORECASTER PASCH

FORECAST POSITIONS AND MAX WINDS

INITIAL      23/0900Z 13.2N  41.4W    45 KT
 12HR VT     23/1800Z 13.3N  41.9W    45 KT
 24HR VT     24/0600Z 13.4N  42.6W    45 KT
 36HR VT     24/1800Z 13.6N  43.2W    50 KT
 48HR VT     25/0600Z 14.2N  44.0W    55 KT
 72HR VT     26/0600Z 16.5N  45.5W    65 KT
 96HR VT     27/0600Z 19.0N  47.0W    70 KT
120HR VT     28/0600Z 21.5N  48.0W    70 KT

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