ZCZC MIATCDAT3 ALL TTAA00 KNHC DDHHMM TROPICAL STORM LORENZO DISCUSSION NUMBER 4 NWS NATIONAL HURRICANE CENTER MIAMI FL AL132013 500 AM AST TUE OCT 22 2013 ALTHOUGH DEEP CONVECTION HAS BEEN INCREASING DURING THE PAST SEVERAL HOURS...MICROWAVE IMAGES INDICATE THAT THE LOW-LEVEL CENTER IS LOCATED NEAR THE SOUTHWESTERN EDGE OF THIS DEEP CLOUDINESS. THE LATEST DVORAK CLASSIFICATIONS FROM TAFB...SAB...AND UW-CIMSS ADT SUPPORT MAINTAINING THE INITIAL WIND SPEED AT 35 KT. LORENZO COULD STRENGTHEN A LITTLE TODAY BEFORE NORTHWESTERLY WIND SHEAR INCREASES SUBSTANTIALLY. THE GFS AND ECMWF MODELS SHOW THE VERTICAL CIRCULATION BECOMING HIGHLY TILTED IN ABOUT 24 HOURS DUE TO THE STRONG SHEAR. IN ADDITION...DRIER AIR AND DECREASING SEA SURFACE TEMPERATURES ALONG THE EXPECTED TRACK OF LORENZO SHOULD AID IN THE WEAKENING PROCESS. THE CYCLONE IS EXPECTED TO DISSIPATE IN 3 TO 4 DAYS...BUT THERE IS SOME GUIDANCE THAT SHOWS THIS OCCURRING SOONER. LORENZO IS GRADUALLY TURNING TO THE RIGHT...AND THE LATEST INITIAL MOTION ESTIMATE IS 070/7. AN EAST-NORTHEASTWARD TO EASTWARD MOTION IS EXPECTED DURING THE NEXT DAY OR SO WHILE THE STORM MOVES IN THE WESTERLY FLOW ON THE NORTH SIDE OF A SUBTROPICAL RIDGE. THE WEAKENING CYCLONE IS FORECAST TO TURN NORTHEASTWARD BY LATE WEDNESDAY OR THURSDAY AHEAD OF AN APPROACHING COLD FRONT. THE MODELS ARE IN GOOD AGREEMENT...AND ONLY SMALL CHANGES WERE MADE TO THE PREVIOUS TRACK FORECAST. FORECAST POSITIONS AND MAX WINDS INIT 22/0900Z 29.5N 53.0W 35 KT 40 MPH 12H 22/1800Z 29.7N 51.7W 40 KT 45 MPH 24H 23/0600Z 29.9N 50.3W 35 KT 40 MPH 36H 23/1800Z 30.2N 49.3W 35 KT 40 MPH 48H 24/0600Z 30.8N 48.3W 30 KT 35 MPH 72H 25/0600Z 32.8N 45.2W 25 KT 30 MPH...POST-TROP/REMNT LOW 96H 26/0600Z...DISSIPATED $$ FORECASTER CANGIALOSI NNNN