HOME	ACTIVE CYCLONES	FORECASTS	IMAGERY	ABOUT TPC	RECONNAISSANCE

ZCZC MIATCDAT4 ALL
TTAA00 KNHC DDHHMM
HURRICANE GERT DISCUSSION NUMBER  44
NATIONAL WEATHER SERVICE MIAMI FL
5 AM EDT WED SEP 22 1999
 
THE INITIAL MOTION ESTIMATE IS 020/20...FASTER THAN EARLIER AS GERT
IS ACCELERATING AHEAD OF THE LARGE MID-TROPOSPHERIC TROUGH OVER THE
EASTERN U.S.  WITH THE ACCELERATION THE OFFICIAL FORECAST TRACK IS
FASTER THAN THE PREVIOUS ADVISORY BUT ON A SIMILAR TRACK...TAKING
GERT OVER EASTERN NEWFOUNDLAND IN ABOUT 30 HOURS.  THIS TRACK IS IN
GOOD AGREEMENT WITH THE INTERPOLATED NOGAPS AND GFDL GUIDANCE.

DVORAK SATELLITE INTENSITY ESTIMATES FROM TAFB AND SAB ARE 77 AND 65
KT RESPECTIVELY...WITH DATA T NUMBERS INDICATING CONTINUED
WEAKENING.  DEEP CONVECTION NEAR THE CENTER IS DECREASING ALTHOUGH
THERE IS STILL SOME IN THE NORTHWEST QUADRANT.  THE OFFICIAL
INTENSITY IS LOWERED TO 75 KT WITH THIS ADVISORY.  VERY COLD SSTS
SHOULD BE ENCOUNTERED IN 24 HOURS.  THE OFFICIAL FORECAST IS IN GOOD
AGREEMENT WITH SHIPS AND GFDL GUIDANCE SHOWING ABOUT 55 KT AS GERT
APPROACHES NEWFOUNDLAND.  

THE AVIATION MODEL LOSES THE LOW LEVEL CIRCULATION AFTER ABOUT 36
HOURS AS IT IS ABSORBED INTO THE LARGER TROUGH.  THE OFFICIAL
FORECAST CALLS FOR AN EXTRATROPICAL TRANSITION AT 36 HOURS AND
DISSIPATION/ABSORPTION AFTER 48 HOURS.

FRANKLIN
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     22/0900Z 37.2N  60.0W    75 KTS
12HR VT     22/1800Z 40.8N  58.3W    65 KTS
24HR VT     23/0600Z 45.2N  55.0W    55 KTS
36HR VT     23/1800Z 49.5N  50.5W    50 KTS...EXTRATROPICAL
48HR VT     24/0600Z 55.5N  45.0W    40 KTS...EXTRATROPICAL
72HR VT     25/0600Z...DISSIPATED
 
NNNN