000 WTPZ41 KNHC 311439 TCDEP1 TROPICAL STORM HENRIETTE DISCUSSION NUMBER 4 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP112007 800 AM PDT FRI AUG 31 2007 RADAR FROM ACAPULCO AND MICROWAVE DATA INDICATE THAT HENRIETTE IS GRADUALLY BECOMING BETTER ORGANIZED WHILE VISIBLE SATELLITE IMAGES SHOW A VERY LARGE AREA OF CLOUDINESS AND THUNDERSTORMS. THE CENTER OF THE STORM APPEARS TO BE LOCATED ON THE EASTERN PORTION OF THE CONVECTION DUE TO EASTERLY SHEAR. IN ADDITION...A PORTION OF THE CIRCULATION IS INTERACTING WITH LAND. INITIAL INTENSITY IS SET AT 35 KNOTS. A GRADUAL STRENGTHENING IS INDICATED SINCE THE OCEAN IS WARM AND THE SHEAR IS FORECAST TO RELAX GRADUALLY. THE OFFICIAL FORECAST IS CONSISTENT WITH SHIPS AND LGEM INTENSITY MODELS. HENRIETTE IS MOVING TOWARD THE WEST-NORTHWEST OR 300 DEGREES AT 9 KNOTS. ON THIS TRACK...THE CORE OF THE CYCLONE WILL BE MOVING NOT TOO FAR FROM THE SOUTHWEST MEXICAN COAST AND ANY DEVIATION TO THE NORTH WOULD BRING STRONGER WINDS TO THE COAST. A STRONG AND PERSISTENT HIGH PRESSURE SYSTEM OVER THE SOUTHWESTERN UNITED STATES IS FORECAST TO STEER HENRIETTE ON A GENERAL WEST-NORTHWEST TRACK THROUGH 72 HOURS. THEREAFTER...THE FORECAST BECOME UNCERTAIN SINCE THE STEERING CURRENTS WEAKEN AND MODELS DIVERGE. ONE GROUP OF MODELS BRING THE CYCLONE NORTHWARD ACROSS BAJA CALIFORNIA AND THE OTHER GROUP TURNS THE CYCLONE ON A MORE WESTERLY TRACK. THE OFFICIAL FORECAST IS IN THE MIDDLE OF THE LARGE SPREAD AT 96 AND 120 HOUR PERIODS...AND BRINGS HENRIETTA TO THE WEST AND NOT FAR FROM SOUTHERN BAJA CALIFORNIA. FORECAST POSITIONS AND MAX WINDS INITIAL 31/1500Z 15.7N 100.1W 35 KT 12HR VT 01/0000Z 16.4N 101.3W 40 KT 24HR VT 01/1200Z 17.4N 102.8W 50 KT 36HR VT 02/0000Z 18.3N 104.5W 60 KT 48HR VT 02/1200Z 19.0N 106.0W 65 KT 72HR VT 03/1200Z 20.5N 109.0W 70 KT 96HR VT 04/1200Z 22.5N 111.0W 70 KT 120HR VT 05/1200Z 25.0N 113.0W 60 KT $$ FORECASTER AVILA