ZCZC MIATCDAT2 ALL TTAA00 KNHC DDHHMM TROPICAL DEPRESSION OLGA DISCUSSION NUMBER 28 NATIONAL WEATHER SERVICE MIAMI FL 10 AM EST SAT DEC 01 2001 VISIBLE IMAGERY SHOWS A FAIRLY WELL-DEFINED LOW LEVEL CIRCULATION. THE CONVECTION IS AT A MINIMUM THIS MORNING AND IS LOCATED EAST OF THE CENTER. A RECENT QUIKSCAT PASS SHOWS 30 KNOT WINDS UNCONTAMINATED AND A FEW 35 KNOT CONTAMINATED. THERE ARE SEVERAL SHIPS REPORTS WITH 25 KNOTS AND A DRIFTING BUOY HAS 30 KNOTS. SO THE INTENSITY IS KEPT AT 30 KNOTS. THERE IS CURRENTLY 20 TO 25 KNOTS OF NORTHWESTERLY VERTICAL SHEAR ON THE SYSTEM. THE SHIPS MODEL INTERPRETS THE AVIATION MODEL TO WEAKEN THE SHEAR FOR 12 HOURS OR SO AND THEN TO INCREASE IT AGAIN EVEN STRONGER. SO THE SYSTEM COULD PERSIST FOR ANOTHER 24 HOURS BUT IS FORECAST TO DISSIPATE AFTER THAT. THE MOTION OVER THE PAST 18 HOURS SINCE YESTERDAYS LAST VISIBLE IMAGES IS 230/5...BUT THE MOTION FOR THE PAST FEW HOURS APPEARS TO BE ABOUT 270/05 THE AVIATION MODEL SHOWS A WEAKENING OF THE MID-LEVEL RIDGE LOCATED NORTHWEST AND NORTH OF THE DEPRESSION. THIS SHOULD INCREASE THE NORTHWARD COMPONENT OF MOTION AND DECREASE THE WESTWARD COMPONENT. THE FORECAST TRACK IS FOR CONTINUED SLOW FORWARD SPEED AND IS SHIFTED TO THE RIGHT OF THE PREVIOUS ADVISORY BUT IS STILL LEFT OF THE AVIATION AND GFDL MODELS. FORECASTER LAWRENCE FORECAST POSITIONS AND MAX WINDS INITIAL 01/1500Z 22.8N 68.5W 30 KTS 12HR VT 02/0000Z 22.8N 69.3W 30 KTS 24HR VT 02/1200Z 23.1N 70.6W 25 KTS...DISSIPATING 36HR VT 03/0000Z 23.6N 71.8W 25 KTS...DISSIPATING 48HR VT 03/1200Z 24.2N 72.8W 20 KTS...REMNANT LOW 72HR VT 04/1200Z 25.5N 74.0W 20 KTS...REMNANT LOW NNNN