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...FOR INTERGOVERNMENTAL USE ONLY...
TROPICAL STORM ANDREW DISCUSSION NUMBER  18
NATIONAL WEATHER SERVICE MIAMI FL
5 AM EDT FRI AUG 21 1992
 
SATELLITE IMAGES DURING THE PAST FEW HOURS INDICATE THAT ANDREW IS
BECOMING A LITTLE BETTER ORGANIZED. THAT WAS CONFIRMED BY AN AIR
FORCE RESERVED UNIT AIRCRAFT WHICH REPORTED A WELL DEFINED
CIRCULATION...A MINIMUM PRESSURE OF 1006 MB AND A FLIGHT LEVEL PEAK
WIND SPEED OF 53 KNOTS NORTH OF THE CENTER.  THE PLANE ALSO REPORTED
THAT A PARTIAL EYEWALL MAY BE FORMING.  THE SURFACE WIND SPEED IS
NOW ESTIMATED TO BE 50 KNOTS.

LATEST AVAILABLE AVIATION FORECAST INDICATES THAT ANDREW WILL BE
UNDER A DEVELOPING UPPER LEVEL WARM RIDGE AND LOW SHEAR.
EXPERIMENTAL SHIPS92 INTENSITY FORECAST MODEL PREDICTS HURRICANE
INTENSITY IN 36 TO 48 HOURS. SINCE THE POTENTIAL FOR STRENGTHENING
CONTINUES...THE OFFICIAL INTENSITY FORECAST INDICATES THAT ANDREW
MAY BECOME A MINIMAL HURRICANE AT THE END OF THE FORECAST PERIOD. 
  
INITIAL MOTION IS 310/10.  LATEST AVIATION RUN CONTINUES TO SHOW THE
DEVELOPMENT OF A HIGH PRESSURE SYSTEM OVER THE EASTERN U.S. AND THE
ADJACENT ATLANTIC.  THIS COULD FORCE ANDREW INTO A MORE WEST
NORTHWEST TRACK DURING THE NEXT DAY OR TWO...A MOTION THAT IS ALSO
INDICATED BY THE BAM MODELS.  NHC90 KEEPS THE NW TRACK THROUGHOUT
THE FORECAST PERIOD.  THE OFFICIAL FORECAST TRACK IS SIMILAR TO THE
PREVIOUS FORECAST AND CLOSE TO BAM-D WHICH USES A DEEP LAYER MEAN AS
STEERING.  

AVILA
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     21/0900Z 24.3N  63.7W    50 KTS
12HR VT     21/1800Z 25.2N  65.0W    50 KTS
24HR VT     22/0600Z 26.1N  66.7W    55 KTS
36HR VT     22/1800Z 26.9N  68.3W    60 KTS
48HR VT     23/0600Z 27.5N  70.0W    65 KTS
72HR VT     24/0600Z 28.0N  72.0W    65 KTS