ZCZC MIAWRKAD4 LOC TTAA00 KNHC DDHHMM ...FOR INTERGOVERNMENTAL USE ONLY... TROPICAL STORM ANDREW DISCUSSION NUMBER 14 NATIONAL WEATHER SERVICE MIAMI FL 5 AM EDT THU AUG 20 1992 ANDREW CONTINUES TO BE POORLY ORGANIZED ON SATELLITE IMAGERY. THERE ARE NO BANDING FEATURES...ONLY INTERMITTENT BURSTS OF CONVECTION WHICH CONTINUE TO BE SHEARED NORTHEASTWARD FROM THE ESTIMATED CENTER. THE CREW OF THE RECON AIRCRAFT WAS NOT ABLE TO LOCATE A CENTER...HOWEVER A 54 KNOT WIND GUST WAS REPORTED AT THE 5000 FT FLIGHT LEVEL IN AN AREA OF STRONG CONVECTION. WE WILL HAVE TO WAIT FOR VISIBLE SATELLITE IMAGERY AND THE FIRST DAYLIGHT RECON TO DETERMINE WHETHER A CLOSED CIRCULATION STILL EXISTS ON THE SURFACE. THE LATEST AVN RUN OF THE NMC GLOBAL SPECTRAL MODEL...AS IN PREVIOUS RUNS...INSISTS THAT THE UPPER TROPOSPHERIC ENVIRONMENT WILL BECOME MUCH MORE CONDUCIVE FOR STRENGTHENING IN ABOUT 24 HOURS...IF ANDREW CAN SURVIVE UNTIL THAT TIME. IT IS ALSO WORTHWHILE TO NOTE THAT THE INITIAL STATE OF THE AVN MODEL WINDS AT 200 MB LOOK REALISTIC IN COMPARISON TO OBSERVED CIRRUS LEVEL MOTIONS AROUND THE STORM. THIS MIGHT GIVE SOME CREDIBILITY TO THE MODEL FORECAST. AGAIN...THE MAIN QUESTION IS WHETHER THE SYSTEM WILL WITHSTAND THE SOUTHWESTERLY SHEARING FOR MUCH LONGER. THE TRACK FORECAST...WITH AN INITIAL MOTION ABOUT THE SAME AS SIX HOURS EARLIER...IS AN UPDATE OF THE PREVIOUS PACKAGE. THERE IS A SUBSTANTIAL SPREAD BETWEEN THE MORE STATISTICALLY-BASED OBJECTIVE AIDS...NHC90 AND CLIPER...AND THE DYNAMICAL MODELS...QLM AND BAM. THE STATISTICAL GUIDANCE TURNS ANDREW MORE NORTHWARD. THE AVN MODEL PREDICTS A DEEP LAYER RIDGE TO BUILD OVER THE SOUTHWEST ATLANTIC. THIS WOULD FAVOR A MORE WESTWARD TRACK WITH TIME AS SHOWN BY THE DYNAMICAL TRACK GUIDANCE. THE OFFICAL FORECAST...AS BEFORE...IS A COMPROMISE BETWEEN THE TWO BUT LEANS MORE TOWARD THE DYNAMICAL GUIDANCE. PASCH FORECAST POSITIONS AND MAX WINDS INITIAL 20/0900Z 21.0N 61.0W 40 KTS 12HR VT 20/1800Z 22.2N 62.7W 40 KTS 24HR VT 21/0600Z 23.3N 64.7W 45 KTS 36HR VT 21/1800Z 24.3N 66.4W 50 KTS 48HR VT 22/0600Z 24.8N 68.0W 55 KTS 72HR VT 23/0600Z 25.5N 70.0W 55 KTS