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...FOR INTERGOVERNMENTAL USE ONLY...
TROPICAL STORM ANDREW DISCUSSION NUMBER  15
NATIONAL WEATHER SERVICE MIAMI FL
11 AM EDT THU AUG 20 1992
 
SO FAR THIS MORNING... AIR FORCE RECONNAISSANCE REPORTS INDICATE A
BROAD... POORLY ORGANIZED CENTER WITH THE LOWEST CENTRAL PRESSURE
NEAR 1015 MB AND MAXIMUM SUSTAINED WINDS AT 1500 FEET OF 54 KNOTS.
NEARBY ENVIRONMENTAL PRESSURES OF 1020 MB APPARENTLY ARE SUFFICIENT
TO SUSTAIN THOSE WINDS.  SATELLITE PICTURES ARE STILL IMPRESSIVE FOR
A SYSTEM THAT HAS GONE THROUGH SUCH A STRUGGLE.

ACCORDING TO WATER VAPOR IMAGERY... THE STRUGGLE MAY BE ENDING SOON
AS THE LOW NORTHEAST OF ANDREW MOVES NORTHEASTWARD... AND THE
TRAILING TROUGH COLLAPSES.  HOWEVER... THERE IS SOME QUESTION
CONCERNING THE INFLUENCE OF THE TROUGH NEAR PUERTO RICO.  IF IT
CLOSES OFF... THIS COULD IMPART A WESTWARD MOTION TO ANDREW. 

THE OFFICIAL TRACK FORECAST ESSENTIALLY FOLLOWS THAT IN THE PREVIOUS
ADVISORY AND REPRESENTS A BLEND OF MORE DIVERGENT MODEL PREDICTIONS. 
THE BAM RUNS AND QLM INDICATE A MORE WESTERLY TRACK...WHEREAS NHC90
CONTINUES A NORTHWEST TRACK.  A MODEL CALLED VICBAR TURNS THE SYSTEM
MORE NORTHWARD AND THE PRINCETON GFDL MODEL 36 HOURS AGO SHOWS
POSITIONS CLOSE TO OUR TRACK.   

THE INTENSITY SCENARIO REMAINS THE SAME.  SOME STRENGTHENING IS
POSSIBLE IF ANDREW SURVIVES THROUGH THE DAY.

GERRISH


 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     20/1500Z 21.3N  61.3W    40 KTS
12HR VT     21/0000Z 22.2N  62.4W    40 KTS
24HR VT     21/1200Z 23.3N  64.0W    45 KTS
36HR VT     22/0000Z 24.2N  65.6W    50 KTS
48HR VT     22/1200Z 24.9N  67.4W    55 KTS
72HR VT     23/1200Z 26.0N  71.0W    55 KTS