000
WTNT44 KNHC 232037
TCDAT4
TROPICAL STORM LISA DISCUSSION NUMBER  12
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL142010
500 PM AST THU SEP 23 2010
 
MICROWAVE DATA A FEW HOURS AGO GAVE US A HINT THAT LISA WAS BECOMING
A LITTLE BETTER ORGANIZED...AND NOW CONVENTIONAL IMAGES SHOW MORE
SYMMETRIC CONVECTION AROUND THE CENTER WITH FAIR OUTFLOW.
SATELLITE INTENSITY ESTIMATES FROM TAFB AND SAB INCREASED TO 2.5 ON
THE DVORAK SCALE. BASED ON THESE ESTIMATES...THE INITIAL INTENSITY
HAS BEEN ADJUSTED UPWARD TO 35 KNOTS AND LISA HAS ONCE AGAIN REACHED
TROPICAL STORM STATUS.  THERE IS A SMALL OPPORTUNITY OF 24 TO 36
HOURS FOR LISA TO STRENGTHEN A LITTLE BEFORE THE SHEAR INCREASES. A
GRADUAL WEAKENING IS ANTICIPATED THEREAFTER.

LISA HAS BEEN MEANDERING OR NEARLY STATIONARY FOR THE PAST FEW HOURS
AND WILL LIKELY CONTINUE TO BE TRAPPED WITHIN VERY WEAK STEERING
CURRENTS FOR THE NEXT 12 HOUR OR SO.  THE RIDGE TO THE EAST OF THE
CYCLONE IS EXPECTED TO BUILD AS A SHARP TROUGH TO THE NORTH MOVES
OUT OF THE AREA.  THIS NEW STEERING PATTERN WILL FORCE LISA ON A
GENERAL NORTH TO NORTHWEST TRACK DURING THE NEXT FIVE DAYS. TRACK
MODEL OUTPUT RESEMBLES A FAN...WITH TRACKS VARYING FROM THE
WEST-NORTHWEST TO THE NORTHEAST. THE OFFICIAL FORECAST IS IN THE
MIDDLE OF THE LARGE GUIDANCE ENVELOPE AND IS HIGHLY UNCERTAIN. 
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      23/2100Z 17.5N  28.6W    35 KT
 12HR VT     24/0600Z 17.5N  28.5W    40 KT
 24HR VT     24/1800Z 19.0N  28.7W    45 KT
 36HR VT     25/0600Z 20.5N  29.5W    35 KT
 48HR VT     25/1800Z 22.0N  30.5W    35 KT
 72HR VT     26/1800Z 24.0N  32.0W    30 KT
 96HR VT     27/1800Z 26.0N  34.0W    25 KT
120HR VT     28/1800Z 28.5N  36.5W    20 KT...POST-TROP/REMNT LOW
 
$$
FORECASTER AVILA