ZCZC MIATCDEP4 ALL TTAA00 KNHC DDHHMM HURRICANE LESTER DISCUSSION NUMBER 21 NATIONAL WEATHER SERVICE MIAMI FL 8 PM PDT MON OCT 19 1998 LESTER CONTINUES TO UNDERGO EAST/NORTHEASTERLY VERTICAL WIND SHEAR ...ASSOCIATED WITH THE MID-TO UPPER LEVEL LOW CURRENTLY OVER NORTHERN GUATEMALA....WHICH IS INHIBITING THE OUTFLOW NORTH AND EAST OF THE CENTER. HOWEVER...AS THE SHIPS INTENSITY MODEL INDICATED SOME STRENGTHENING WAS LIKELY AND...LOW AND BEHOLD... DVORAK ESTIMATES ARE BACK UP. INITIAL INTENSITY IS SET AT 85 KTS AND INCREASED TO 90 KTS THROUGH REMAINDER OF FORECAST PERIOD PER SHIPS GUIDANCE. THE INITIAL MOTION IS NOW 285/08 KNOTS. MODEL GUIDANCE FALLS INTO TWO SCENARIOS. BAMD...LBAR...UKMET AND GFDL BEGIN RECURVATURE AROUND 110 W UNDER THE INFLUENCE OF A MID-LATITUDE TROUGH. REMAINING MODELS MOVE THE SYSTEM WEST-NORTHWEST THROUGH 72 HOURS UNDER INFLUENCE OF MID-TROPOSPHERIC RIDGE TO THE NORTH THAT IS NOT MODIFIED BY MID-LATITUDE TROUGH. FORECAST CALLS FOR GENERAL WEST TO WEST-NORTHWEST COURSE FOR THE NEXT DAY OR SO WITH A GRADUAL TURN TOWARD THE NORTHWEST. THIS TRACK FORECAST IS SLIGHTLY TO THE RIGHT OF THE PREVIOUS PACKAGE. JARVINEN FORECAST POSITIONS AND MAX WINDS INITIAL 20/0300Z 14.9N 103.4W 85 KTS 12HR VT 20/1200Z 15.2N 104.6W 90 KTS 24HR VT 21/0000Z 15.7N 106.4W 90 KTS 36HR VT 21/1200Z 16.4N 108.1W 90 KTS 48HR VT 22/0000Z 17.3N 109.8W 90 KTS 72HR VT 23/0000Z 18.6N 111.7W 90 KTS NNNN