HOME	PRODUCTS	FORECASTS	IMAGERY	ABOUT TPC	RECONNAISSANCE

ZCZC MIATCDAT2 ALL
TTAA00 KNHC DDHHMM
TROPICAL STORM HELENE DISCUSSION NUMBER  15
NATIONAL WEATHER SERVICE MIAMI FL
11 PM EDT THU SEP 21 2000
 
OVERALL THE TROPICAL CYCLONE REMAINS QUITE DISORGANIZED WITH LITTLE
EVIDENCE OF BANDING FEATURES ON SATELLITE IMAGERY.   HOWEVER
A SMALL PATCH OF DEEP CONVECTION REGENERATED NEAR THE CENTER WHICH
MIGHT ALLOW FOR SOME SLIGHT INTENSIFICATION DURING THE NEXT FEW
HOURS...OR AT LEAST MAINTAIN THE CURRENT INTENSITY UNTIL LANDFALL.
RADIOSONDE AND VAD DATA FROM THE EGLIN WSR-88D SUGGEST SOME
WEAKENING OF THE HIGH-LEVEL WESTERLY WINDS OVER THE NORTHEAST GULF
COASTAL AREA...BUT THERE IS STILL QUITE A BIT OF SHEAR OVER HELENE.
THEREFORE SIGNIFICANT STRENGTHENING IS UNLIKELY BEFORE LANDFALL.
HAVING SAID ALL THAT...IT WOULD NOT TAKE MUCH OF AN INCREASE IN
WINDS TO MAKE HELENE A HURRICANE.
 
INITIAL MOTION IS A LITTLE FASTER...NOW 360/13.  THE STORM CONTINUES
TO BE STEERED AROUND THE NORTHWESTERN PERIPHERY OF A LARGE DEEP-
LAYER ANTICYCLONE.  500 MB WINDS FROM THE 00Z RADIOSONDE RUNS
INDICATE THAT HELENES HEADING SHOULD CHANGE TO THE NORTH-NORTHEAST
VERY SOON...AND THE CENTER SHOULD REACH THE PANHANDLE COAST IN LESS
THAN 12 HOURS.  A GRADUAL INCREASE IN FORWARD SPEED IS EXPECTED OVER
THE NEXT FEW DAYS.  THE OFFICIAL FORECAST IS VERY SIMILAR TO THE
PREVIOUS ONE AND IS IN GOOD AGREEMENT WITH OUR VARIOUS OBJECTIVE
GUIDANCE MODELS.  LATE IN THE FORECAST PERIOD...HELENE IS EXPECTED
TO BECOME INVOLVED WITH A FRONTAL ZONE MOVING OFF THE NORTHEAST U.S.
COAST AND BECOME EXTRATROPICAL.
 
FORECASTER PASCH
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     22/0300Z 29.1N  87.1W    55 KTS
12HR VT     22/1200Z 30.8N  86.1W    55 KTS...INLAND
24HR VT     23/0000Z 33.0N  84.0W    35 KTS...INLAND
36HR VT     23/1200Z 35.0N  81.0W    25 KTS...INLAND
48HR VT     24/0000Z 36.5N  76.5W    30 KTS...INLAND
72HR VT     25/0000Z 39.0N  67.0W    30 KTS...EXTRATROPICAL
 
NNNN