Tropical Depression EIGHT-E
ZCZC MIATCDEP3 ALL TTAA00 KNHC DDHHMM TROPICAL DEPRESSION EIGHT-E DISCUSSION NUMBER 1 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP082006 800 PM PDT MON JUL 31 2006 SATELLITE IMAGERY INDICATES THAT THE DISTURBANCE SOUTHWEST OF ACAPULCO MEXICO HAS ACQUIRED ENOUGH DEEP CONVECTION AND BECOME SUFFICIENTLY ORGANIZED TO BE UPGRADED TO A 30 KT TROPICAL DEPRESSION. THIS IS SUPPORTED BY UNANIMOUS SATELLITE INTENSITY ESTIMATES OF 30 KT FROM BOTH TAFB AND SAB. THE DEPRESSION IS CURRENTLY UNDER THE INFLUENCE OF MODERATE EASTERLY SHEAR AND THE CENTER IS ESTIMATED TO BE LOCATED NEAR THE EAST SIDE OF AN AREA OF DEEP CONVECTION. GLOBAL MODELS INDICATE THE SHEAR MAY RELAX A BIT ALLOWING THE CYCLONE AN OPPORTUNITY TO STRENGTHEN OVER THE NEXT COUPLE OF DAYS. TOWARDS THE END OF THE FORECAST...THE DEPRESSION WILL BE NEARING COOLER WATERS AND A MORE STABLE AIR MASS. THE OFFICIAL FORECAST IS CONSISTENT WITH THE SHIPS MODEL. THE INITIAL MOTION ESTIMATE IS AN UNCERTAIN 280/9. THE CYCLONE IS CURRENTLY BEING STEERED AROUND THE WESTERN PERIPHERY OF A DEEP-LAYER RIDGE OVER CENTRAL MEXICO BUT THE VERTICAL SHEAR IS CREATING ERRATIC SHORT-TERM MOTION. THE OFFICIAL FORECAST SHOWS THE CYCLONE CONTINUING TO MOVE IN A GENERAL WEST-NORTHWESTWARD DIRECTION THROUGH MOST OF THE FORECAST PERIOD AS A BROAD TROUGH DEVELOPS OFF THE WEST COAST OF THE UNITED STATES. TOWARD THE END OF THE FORECAST PERIOD...THE DYNAMICAL MODELS BEGIN TO DIVERGE. SOME OF THE MODELS INDICATE THE TROUGH WILL LIFT NORTHWARD AND INCREASED RIDGING WILL DEVELOP TO THE NORTH OF THE CYCLONE WHILE OTHER MODELS SHOW THE TROUGH REMAINING IN PLACE. THE OFFICIAL FORECAST ASSUMES THE TROUGH WILL LIFT SUFFICIENTLY NORTH TO ALLOW A GRADUAL TURN TOWARDS THE WEST. FORECAST POSITIONS AND MAX WINDS INITIAL 01/0300Z 12.7N 104.6W 30 KT 12HR VT 01/1200Z 13.1N 106.0W 35 KT 24HR VT 02/0000Z 13.7N 107.7W 40 KT 36HR VT 02/1200Z 14.3N 109.4W 45 KT 48HR VT 03/0000Z 14.7N 111.7W 50 KT 72HR VT 04/0000Z 15.0N 115.3W 50 KT 96HR VT 05/0000Z 16.1N 119.0W 45 KT 120HR VT 06/0000Z 18.0N 122.5W 40 KT $$ FORECASTER RHOME/FRANKLIN NNNN