000 WTPZ44 KNHC 040837 TCDEP4 TROPICAL DEPRESSION FOUR-E DISCUSSION NUMBER 1 NWS NATIONAL HURRICANE CENTER MIAMI FL EP042012 200 AM PDT WED JUL 04 2012 GEOSTATIONARY SATELLITE IMAGERY AND A RECENT ASCAT PASS INDICATE THAT THE AREA OF LOW PRESSURE LOCATED SEVERAL HUNDRED MILES SOUTH OF MANZANILLO MEXICO HAS ACQUIRED A SUFFICIENTLY WELL-DEFINED CENTER AND ENOUGH ORGANIZATION OF THE THUNDERSTORM ACTIVITY FOR THE SYSTEM TO BE CLASSIFIED AS A TROPICAL DEPRESSION. THE ASCAT DATA SHOWED AN AREA OF 25-30 KT WINDS TO THE SOUTHEAST OF THE CENTER...THEREFORE THE INITIAL INTENSITY IS SET AT 30 KT. SINCE THE DEPRESSION IS STILL IN ITS FORMATIVE STAGE...THE INITIAL MOTION ESTIMATE IS A SOMEWHAT UNCERTAIN 295/10 KT. THE CYCLONE IS FORECAST TO CONTINUE MOVING ON THIS GENERAL HEADING AND SPEED DURING THE NEXT DAY OR SO AS IT REMAINS ON THE SOUTHWESTERN PERIPHERY OF A MID-LEVEL RIDGE OVER NORTHERN MEXICO AND THE CENTRAL UNITED STATES. THE RIDGE IS FORECAST TO STRENGTHEN AND BUILD WESTWARD DURING THE LATTER PART OF THE WEEK. THIS IS EXPECTED TO CAUSE THE CYCLONE TO TURN WESTWARD IN A COUPLE OF DAYS AND A GENERAL WESTWARD MOTION SHOULD THEN CONTINUE THROUGH THE REMAINDER OF THE FORECAST PERIOD. THE TRACK GUIDANCE IS IN GOOD AGREEMENT ON THIS SCENARIO AND THE OFFICIAL FORECAST IS NEAR THE MIDDLE OF THE MODEL ENVELOPE. THE DEPRESSION IS FORECAST TO REMAIN OVER WARM WATER DURING THE NEXT 2-3 DAYS...HOWEVER MODERATE NORTH-NORTHEASTERLY SHEAR IS EXPECTED TO PERSIST DURING MOST OF THAT TIME. AS A RESULT...ONLY GRADUAL STRENGTHENING IS SHOWN BY MOST OF THE INTENSITY MODELS. THE OFFICIAL FORECAST LIES BETWEEN THE SHIPS AND LGEM GUIDANCE. SOME WEAKENING IS SHOWN BY DAY 5 AS THE CYCLONE IS FORECAST TO MOVE OVER COOLER WATERS BY THAT TIME. FORECAST POSITIONS AND MAX WINDS INIT 04/0900Z 12.3N 105.5W 30 KT 35 MPH 12H 04/1800Z 13.0N 106.8W 35 KT 40 MPH 24H 05/0600Z 13.8N 108.5W 40 KT 45 MPH 36H 05/1800Z 14.4N 110.4W 45 KT 50 MPH 48H 06/0600Z 14.7N 112.4W 50 KT 60 MPH 72H 07/0600Z 15.0N 116.6W 60 KT 70 MPH 96H 08/0600Z 15.2N 121.0W 60 KT 70 MPH 120H 09/0600Z 15.8N 125.5W 50 KT 60 MPH $$ FORECASTER BROWN