000 WTPZ44 KNHC 110237 TCDEP4 TROPICAL DEPRESSION NINE-E DISCUSSION NUMBER 6 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP092009 800 PM PDT MON AUG 10 2009 THE CENTER OF THE DEPRESSION REMAINS EXPOSED TO THE WEST OF THE DEEP CONVECTION...DUE TO WESTERLY SHEAR. MORE RECENTLY THE CONVECTION HAS DEVELOPED A LITTLE CLOSER TO THE CENTER AND IS EXHIBITING SLIGHTLY MORE CURVATURE. HOWEVER...THE DVORAK DATA T-NUMBERS FROM BOTH AGENCIES ARE 2.0...WHICH SUPPORT MAINTAINING THE INTENSITY AT 30 KT. THE DEPRESSION IS CURRENTLY PASSING NEAR THE BASE OF AN UPPER-LEVEL TROUGH WHICH HAS BEEN RESPONSIBLE FOR THE SHEAR. THE GLOBAL MODELS SUGGEST THAT ONCE THE CYCLONE MOVES WEST OF THE TROUGH AXIS...THE UPPER-LEVEL WINDS SHOULD DECREASE AND TURN NORTHEASTERLY. THIS IS EXPECTED TO RESULT IN A RELAXATION OF THE SHEAR IN ABOUT 24-36 HOURS. AFTER THAT TIME... THE STATISTICAL GUIDANCE PREDICTS MODEST STRENGTHENING THROUGH 72 HOURS. ON THE OTHER HAND...THE DYNAMICAL MODELS FORECAST NO STRENGTHENING AND MANY SHOW DISSIPATION WITHIN A COUPLE OF DAYS. THE FUTURE OF DEPRESSION APPEARS TO BE HIGHLY DEPENDANT ON ITS SURVIVAL DURING THE NEXT DAY OR SO. GIVEN THIS UNCERTAINTY...THE OFFICIAL FORECAST WILL FOLLOW THE PREVIOUS ADVISORY AND THE DYNAMICAL GUIDANCE...WHICH KEEP THE CYCLONE BELOW TROPICAL STORM STRENGTH. THE DEPRESSION IS MOVING WESTWARD AT ABOUT 10 KT. THE TRACK GUIDANCE IS IN GOOD AGREEMENT ON A GENERAL WESTWARD MOTION DURING THE NEXT 2-3 DAYS...THEREAFTER THE MODELS WHICH WEAKEN THE CYCLONE TURN IT WEST-SOUTHWESTWARD. THE OFFICIAL FORECAST ASSUMES THAT THE CYCLONE WILL REMAIN A SHALLOW SYSTEM AND NOT GAIN MUCH LATITUDE. THE NEW NHC TRACK FORECAST IS AN UPDATE OF THE PREVIOUS TRACK AND REMAINS CLOSE TO THE FORWARD SPEED OF THE MODEL CONSENSUS. FORECAST POSITIONS AND MAX WINDS INITIAL 11/0300Z 15.1N 125.4W 30 KT 12HR VT 11/1200Z 15.3N 126.9W 30 KT 24HR VT 12/0000Z 15.5N 128.7W 30 KT 36HR VT 12/1200Z 15.6N 130.6W 30 KT 48HR VT 13/0000Z 15.6N 132.5W 30 KT 72HR VT 14/0000Z 15.6N 136.3W 25 KT 96HR VT 15/0000Z 15.5N 140.5W 20 KT...REMNANT LOW 120HR VT 16/0000Z...DISSIPATED $$ FORECASTER BROWN