ZCZC MIATCDAT3 ALL TTAA00 KNHC DDHHMM TROPICAL DEPRESSION THIRTEEN DISCUSSION NUMBER 2 NATIONAL WEATHER SERVICE MIAMI FL 5 AM EDT THU OCT 22 1998 SATELLITE IMAGES SUGGEST LITTLE CHANGE IN THE STRENGTH OF THE SYSTEM OVER THE PAST SEVERAL HOURS. ALTHOUGH DEEP CONVECTION REMAINS FAIRLY STRONG...THERE IS NOT MUCH EVIDENCE OF BANDING FEATURES SO FAR. NORTHERLY SHEAR HAS BEEN AFFECTING THE DEPRESSION...PROBABLY DUE TO AN UPPER LEVEL CYCLONE LOCATED A FEW HUNDRED MILES TO THE NORTHEAST. HOWEVER...THE NCEP GLOBAL MODEL FORECASTS AN INCREASINGLY FAVORABLE UPPER-LEVEL ENVIRONMENT OVER THE WESTERN CARIBBEAN DURING THE NEXT FEW DAYS. THEREFORE...STRENGTHENING IS FORECAST AS IN THE PREVIOUS ADVISORY AND IN CLOSE AGREEMENT WITH THE STATISTICAL HURRICANE INTENSITY PREDICTION SCHEME. AN EARLIER RECON FIX SHOWED THAT THE CENTER WAS NEAR THE NORTHERN EDGE OF THE DEEP CONVECTION. THIS WAS ALSO SHOWN BY AN 85 GHZ IMAGE FROM THE NAVAL RESEARCH LAB MONTEREY TROPICAL CYCLONE HOMEPAGE. THE CURRENT LOCATION IS RATHER UNCERTAIN BUT THE DEPRESSION APPEARS TO HAVE MOVED MOSTLY WESTWARD SINCE THE LAST ADVISORY. A LARGE MID-LATITUDE TROUGH WILL BE SWEEPING OFF THE SOUTHEAST U.S. COAST DURING THE NEXT DAY OR SO. THE 06Z RUN OF THE NCEP GLOBAL MODEL SHOWS A 500 MB WEAKNESS EXTENDING SOUTHWESTWARD FROM THE TROUGH INTO THE NORTHWEST CARIBBEAN DURING THE FORECAST PERIOD...WHICH IS EXPECTED TO CAUSE THE TROPICAL CYCLONE TO TURN TOWARD THE NORTHWEST. THIS IS SHOWN BY MOST OF THE OBJECTIVE TRACK PREDICTION MODELS ALTHOUGH THE GFDL SHOWS A MORE NORTHWARD TRACK...WITH A TURN BACK TO THE WEST NEAR THE END OF THE PERIOD. THE CURRENT OFFICIAL FORECAST IS VERY CLOSE TO THAT FROM THE PREVIOUS PACKAGE AND IS ALSO VERY SIMILAR TO THE MEDIUM-DEPTH BAM TRACK. INTERESTS IN THE WESTERN CARIBBEAN SHOULD CLOSELY MONITOR THE PROGRESS OF THIS SYSTEM SINCE TROPICAL STORM OR HURRICANE WATCHES AND WARNINGS MAY BE REQUIRED FOR SOME PORTION OF THE AREA LATER TODAY. PASCH FORECAST POSITIONS AND MAX WINDS INITIAL 22/0900Z 12.7N 78.5W 30 KTS 12HR VT 22/1800Z 13.0N 79.5W 40 KTS 24HR VT 23/0600Z 14.0N 80.5W 50 KTS 36HR VT 23/1800Z 15.0N 81.5W 60 KTS 48HR VT 24/0600Z 16.2N 82.2W 65 KTS 72HR VT 25/0600Z 18.0N 83.0W 70 KTS NNNN