ZCZC MIATCDEP4 ALL TTAA00 KNHC DDHHMM TROPICAL STORM LESTER DISCUSSION NUMBER 42 NATIONAL WEATHER SERVICE MIAMI FL 1 AM PST SUN OCT 25 1998 SATELLITE IMAGERY SUGGESTS THAT THE LOW-LEVEL CENTER IS EXPOSED TO THE NORTHWEST OF THE CONVECTIVE CLUSTER. INITIAL INTENSITY REMAINS AT 40 KNOTS WHICH IS A COMPROMISE BETWEEN VARIOUS DVORAK INTENSITY ESTIMATES. SHIPS GUIDANCE INDICATES WEAKENING DUE TO INCREASED SHEAR WHILE THE GFDL SHOWS A LITTLE STRENGTHENING. THEREFORE...THE OFFICIAL FORECAST WILL SHOW NO SIGNIFICANT CHANGE. INITIAL MOTION ESTIMATE IS 310/09. HOWEVER...THE DYNAMICAL MODELS ...GFDL...NOGAPS...AND UKMET...ALL INDICATE A SLOW DOWN AS STEERING CURRENTS WEAKEN. OUR CURRENT TRACK IS ADJUSTED CONSIDERABLY BASED ON THIS AND IS A BLEND BETWEEN THE DYNAMICAL MODELS AND THE SHALLOW/MID LAYER BAMS. IF LESTER WERE TO BECOME SIGNIFICANTLY STRONGER THAN FORECAST...A MORE RAPID RECURVATURE TOWARD THE NORTHEAST COULD OCCUR...SIMILAR TO THE DEEP LAYER BAM. MAYFIELD FORECAST POSITIONS AND MAX WINDS INITIAL 25/0900Z 16.9N 114.0W 40 KTS 12HR VT 25/1800Z 17.5N 114.8W 40 KTS 24HR VT 26/0600Z 18.2N 115.3W 40 KTS 36HR VT 26/1800Z 18.7N 115.5W 40 KTS 48HR VT 27/0600Z 19.5N 115.5W 40 KTS 72HR VT 28/0600Z 20.0N 115.0W 40 KTS NNNN