000 WTPZ45 KNHC 130242 TCDEP5 TROPICAL STORM GUILLERMO DISCUSSION NUMBER 3 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP102009 800 PM PDT WED AUG 12 2009 THE CLOUD PATTERN HAS CONTINUED TO BECOME BETTER ORGANIZED AND CONSISTS OF WELL-DEFINED CYCLONICALLY CURVED BANDS WITH DEEP CONVECTION FORMING NEAR THE CENTER. THE OUTFLOW IS ESTABLISHED PRIMARILY ON THE WESTERN SEMICIRCLE. BASED ON SATELLITE ESTIMATES OF 2.5 ON THE DVORAK SCALE FROM BOTH TAFB AND SAB...THE DEPRESSION HAS BEEN UPGRADED TO TROPICAL STORM STATUS WITH AN INITIAL INTENSITY OF 35 KT. GUILLERMO HAS THE OPPORTUNITY TO GAIN SOME STRENGTH BEFORE IT REACHES COOLER WATERS AND STABLE AIR IN ABOUT TWO TO THREE DAYS. NONE OF THE GUIDANCE STRENGTHENS THE CYCLONE SIGNIFICANTLY. GUILLERMO IS MOVING TOWARD THE WEST-NORTHWEST OR 290 DEGREES AT 14 KNOTS. THE CYCLONE IS BEING STEERED BY A WELL-ESTABLISHED DEEP LAYER EASTERLY FLOW SOUTH OF THE SUBTROPICAL RIDGE. GLOBAL MODELS INDICATE THAT THIS GENERAL FLOW PATTERN IS FORECAST TO PERSIST AND PERHAPS BECOME EVEN MORE EASTERLY BEYOND THREE DAYS. GUILLERMO IS EXPECTED TO CONTINUE ON THIS GENERAL TRACK WITH A SMALL BEND TO THE WEST DURING THE LATER PART OF THE FORECAST PERIOD. THIS FORECAST LIES IN THE MIDDLE OF DYNAMICAL GUIDANCE ENVELOPE AND VERY SIMILAR TO THE PREVIOUS OFFICIAL FORECAST. FORECAST POSITIONS AND MAX WINDS INITIAL 13/0300Z 16.2N 119.2W 35 KT 12HR VT 13/1200Z 16.7N 121.5W 40 KT 24HR VT 14/0000Z 17.1N 123.8W 50 KT 36HR VT 14/1200Z 17.5N 126.5W 55 KT 48HR VT 15/0000Z 18.0N 129.0W 50 KT 72HR VT 16/0000Z 18.5N 134.5W 50 KT 96HR VT 17/0000Z 18.5N 140.5W 45 KT 120HR VT 18/0000Z 18.5N 147.0W 40 KT $$ FORECASTER AVILA