000 WTPZ45 KNHC 152039 TCDEP5 TROPICAL DEPRESSION FIFTEEN-E DISCUSSION NUMBER 4 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP152007 200 PM PDT MON OCT 15 2007 DEEP CONVECTION HAS DECREASED DURING THE PAST FEW HOURS...EXPOSING THE LOW-LEVEL CIRCULATION THAT IS NOT EXCEPTIONALLY WELL-DEFINED. A QUIKSCAT OVERPASS AT AROUND 1330Z PROVIDED SEEMINGLY RELIABLE WIND RETRIEVALS OF 25-30 KT...WITH HIGHER VALUES IN THE WESTERN SEMICIRCLE THAT WERE LIKELY INFLATED BY THE CONVECTION AT THE TIME. THE ADVISORY INTENSITY IS MAINTAINED AT 30 KT BASED ON THE QUIKSCAT DATA. THE EASTERLY SHEAR IS FORECAST BY THE DYNAMICAL MODELS TO PERSIST AT ROUGHLY ITS CURRENT MAGNITUDE THROUGHOUT THE NEXT FIVE DAYS...SO SIGNIFICANT STRENGTHENING APPEARS UNLIKELY. MOST OF THE OBJECTIVE INTENSITY MODELS FORECAST A LITTLE STRENGTHENING. THE OFFICIAL FORECAST DOES TOO...BUT LEANS TOWARD THE WEAKER SOLUTIONS GIVEN HOW MUCH THE SYSTEM IS CURRENTLY STRUGGLING IN THE SHEARED ENVIRONMENT. THE CENTER OF THE DEPRESSION HAS BEEN ESSENTIALLY STATIONARY DURING THE PAST 12-18 HOURS. STEERING CURRENTS ARE OBVIOUSLY WEAK...AND MOST OF THE DYNAMICAL MODELS FORECAST LITTLE CHANGE IN THE SURROUNDING SYNOPTIC PATTERN FOR THE NEXT SEVERAL DAYS. THERE IS A WEAK AND NARROW MID-LEVEL RIDGE TO THE NORTH OF THE TROPICAL CYCLONE...BUT THE SYSTEM IS NOT DEEP ENOUGH TO RESPOND...AND THERE ARE NO LOW-LEVEL STEERING MECHANISMS IN PLAY. THE MODEL GUIDANCE TRACKS GO IN ALL KINDS OF DIRECTIONS. SOME OF THEM...INCLUDING THE GFS...FORECAST NO SIGNIFICANT NET MOTION THROUGH THE ENTIRE FORECAST PERIOD...WHICH SUPPORTS THE OFFICIAL FORECAST OF A NEARLY STATIONARY CYCLONE FOR THE NEXT FIVE DAYS. FORECAST POSITIONS AND MAX WINDS INITIAL 15/2100Z 15.1N 108.7W 30 KT 12HR VT 16/0600Z 15.1N 108.7W 35 KT 24HR VT 16/1800Z 15.1N 108.7W 35 KT 36HR VT 17/0600Z 15.1N 108.7W 35 KT 48HR VT 17/1800Z 15.1N 108.7W 35 KT 72HR VT 18/1800Z 15.0N 108.5W 35 KT 96HR VT 19/1800Z 15.0N 108.5W 35 KT 120HR VT 20/1800Z 15.0N 108.5W 35 KT $$ FORECASTER KNABB