000 WTPZ43 KNHC 020239 TCDEP3 TROPICAL DEPRESSION EIGHTEEN-E DISCUSSION NUMBER 4 NWS NATIONAL HURRICANE CENTER MIAMI FL EP182013 800 PM PDT FRI NOV 01 2013 THE STRUCTURE OF THE DEPRESSION HAS CHANGED LITTLE DURING THE LAST SEVERAL HOURS. THE CYCLONE STILL HAS AN ASYMMETRIC CONVECTIVE PATTERN WITH NEARLY ALL OF THE DEEP CLOUDINESS CONFINED TO THE WESTERN HALF OF THE CIRCULATION. IN ADDITION...THE CENTER IS ELONGATED WITH MULTIPLE SWIRLS EVIDENT IN THE LAST FEW VISIBLE IMAGES OF THE DAY. THE INITIAL WIND SPEED IS MAINTAINED AT 30 KT...IN AGREEMENT WITH THE DVORAK CLASSIFICATION FROM TAFB. THE DEPRESSION IS MOVING SLOWLY NORTH-NORTHWESTWARD. A RIDGE CURRENTLY OVER THE GULF OF MEXICO IS EXPECTED TO EXPAND WESTWARD...CAUSING THE SYSTEM TO TURN TOWARD THE WEST-NORTHWEST ON SATURDAY. THAT MOTION SHOULD BE SHORT-LIVED...HOWEVER...AS A LARGE MID- TO UPPER-LEVEL LOW CURRENTLY NEAR 25N 125W MOVES NORTHEASTWARD. THIS CHANGE IN THE STEERING PATTERN SHOULD CAUSE THE CYCLONE TO TURN NORTHWARD AND THEN NORTHEASTWARD LATER IN THE WEEKEND AND EARLY NEXT WEEK. THE NHC TRACK FORECAST BRINGS THE SYSTEM TO THE SOUTH OF THE BAJA CALIFORNIA SUR IN ABOUT 2 DAYS AND OVER WEST- CENTRAL MEXICO IN 2 TO 3 DAYS. EASTERLY SHEAR OF 15-20 KT IS LIKELY THE REASON FOR THE POOR STRUCTURE OF THE DEPRESSION. THE SHEAR IS EXPECTED TO DECREASE DURING THE NEXT COUPLE OF DAYS WHILE THE SYSTEM REMAINS OVER WATERS OF ABOUT 28C...AND THESE ENVIRONMENTAL CONDITIONS COULD ALLOW THE DEPRESSION TO STRENGTHEN TO A TROPICAL STORM. WEAKENING IS FORECAST AFTER THE CYCLONE MAKES LANDFALL...AND IT WILL LIKELY DISSIPATE OVER THE SIERRA MADRE MOUNTAINS IN 3 TO 4 DAYS. THE NHC INTENSITY FORECAST IS SLIGHTLY LOWER THAN THE PREVIOUS ONE...AND IS CLOSE TO THE LATEST MODEL CONSENSUS. FORECAST POSITIONS AND MAX WINDS INIT 02/0300Z 16.9N 108.4W 30 KT 35 MPH 12H 02/1200Z 17.2N 109.4W 30 KT 35 MPH 24H 03/0000Z 17.9N 110.3W 35 KT 40 MPH 36H 03/1200Z 19.1N 110.5W 35 KT 40 MPH 48H 04/0000Z 21.0N 109.8W 35 KT 40 MPH 72H 05/0000Z 26.1N 106.6W 25 KT 30 MPH...POST-TROP/REMNT LOW 96H 06/0000Z...DISSIPATED $$ FORECASTER CANGIALOSI