000 WTNT42 KNHC 100840 TCDAT2 TROPICAL DEPRESSION SEVEN DISCUSSION NUMBER 3 NWS NATIONAL HURRICANE CENTER MIAMI FL AL072012 500 AM AST FRI AUG 10 2012 THE OVERALL ORGANIZATION OF THE DEPRESSION HAS NOT CHANGED OVERNIGHT. A COUPLE OF MICROWAVE OVERPASSES HAVE REVEALED A SMALL...BUT WELL-DEFINED CIRCULATION WITH A SMALL BAND OF CONVECTION TO THE NORTHEAST OF THE CENTER. NOAA BUOY 41041 REPORTED PEAK 1-MINUTE SUSTAINED WINDS OF 29 KT AND A MINIMUM PRESSURE OF 1010.9 MB AS THE CENTER PASSED ABOUT 30 TO 40 N MI SOUTH OF THE BUOY AROUND 0600 UTC. BASED ON THE BUOY OBSERVATIONS AND LACK OF STRUCTURAL CHANGE...THE INITIAL WIND SPEED WILL REMAIN 30 KT. THE CYCLONE IS FORECAST TO MOVE OVER INCREASING SSTS AND REMAIN IN A LOW SHEAR ENVIRONMENT DURING THE NEXT DAY OR SO. HOWEVER...DRY AIR NEAR THE CIRCULATION WILL LIKELY ALLOW FOR ONLY MODEST INTENSIFICATION. THE GLOBAL MODELS INDICATE THAT THE DEPRESSION WILL ENCOUNTER INCREASING SOUTHERLY TO SOUTHWESTERLY UPPER-LEVEL WINDS AS IT NEARS THE WINDWARD ISLANDS. THIS INCREASING SHEAR WILL LIKELY HALT ANY INTENSIFICATION. THE OFFICIAL INTENSITY FORECAST IS SIMILAR TO THE PREVIOUS ADVISORY AND IS CLOSEST TO THE SHIPS GUIDANCE. IT SHOULD BE NOTED THAT BOTH THE GFS AND ECMWF WEAKEN THE SYSTEM AND SHOW IT BECOMING AN OPEN WAVE IN THE EASTERN CARIBBEAN. FOR NOW...THE NHC FORECAST DOES NOT INDICATE WEAKENING...BUT THAT IS ONE POSSIBILITY GIVEN THAT THE SYSTEM IS SMALL...MAKING IT MORE PRONE TO THE EXPECTED INCREASE IN SHEAR IN A COUPLE OF DAYS. THE DEPRESSION CONTINUES MOVING QUICKLY WESTWARD OR 270 DEGREES AT 17 KT. THE CYCLONE IS EXPECTED TO REMAIN ON THIS GENERAL HEADING AND SPEED DURING THE NEXT FEW DAYS AS IT IS STEERED WESTWARD BY A MID-LEVEL RIDGE OVER THE CENTRAL ATLANTIC. BEYOND THREE DAYS THE RIDGE IS EXPECTED TO WEAKEN WHICH WOULD CAUSE THE CYCLONE TO TURN WEST-NORTHWESTWARD. THE NHC FORECAST REMAINS ALONG THE SOUTHERN SIDE OF THE GUIDANCE ENVELOPE AND IS IN BEST AGREEMENT WITH THE GFS MODEL. FORECAST POSITIONS AND MAX WINDS INIT 10/0900Z 13.6N 47.2W 30 KT 35 MPH 12H 10/1800Z 13.6N 49.9W 35 KT 40 MPH 24H 11/0600Z 13.7N 53.3W 40 KT 45 MPH 36H 11/1800Z 13.9N 56.8W 45 KT 50 MPH 48H 12/0600Z 14.3N 60.0W 45 KT 50 MPH 72H 13/0600Z 15.3N 66.6W 45 KT 50 MPH 96H 14/0600Z 16.5N 73.0W 45 KT 50 MPH 120H 15/0600Z 17.5N 79.5W 45 KT 50 MPH $$ FORECASTER BROWN