WDPN32 PGTW 181500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 23W (MARIA) WARNING NR 18// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM 23W (MARIA), LOCATED APPROXIMATELY 780 NM EAST OF TOKYO, JAPAN, HAS TRACKED EASTWARD AT 14 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY (EIR) SHOWS CENTRAL CONVECTION HAS BECOME SIGNIFICANTLY SHEARED TO THE EAST, FULLY EXPOSING A RAGGED LOW LEVEL CIRCULATION CENTER (LLCC), AS EVIDENCED ON A 181053Z METOP-A MICROWAVE IMAGE. THE INITIAL POSITION IS BASED ON THE MICROWAVE IMAGE WITH FAIR CONFIDENCE. THE INITIAL INTENSITY IS BASED ON THE 180530Z DVORAK ESTIMATE FROM PGTW. UPPER LEVEL ANALYSIS INDICATES THE SYSTEM IS WELL NORTH OF THE RIDGE AXIS IN AN AREA OF STRONG (GREATER THAN 30 KNOTS) VERTICAL WIND SHEAR. THE CYCLONE IS TRACKING ALONG THE NORTHERN PERIPHERY OF THE SUBTROPICAL RIDGE (STR) TO THE SOUTH. 3. FORECAST REASONING. A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING BULLETIN. B. TS MARIA WILL CONTINUE TO TRACK ALONG THE NORTHERN EDGE OF THE STR. WITH DECREASING SSTS, PERSISTENT HIGH VWS, AND DEFORMATION OF THE LLCC, IT WILL GRADUALLY WEAKEN, DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER BY TAU 24. NUMERIC GUIDANCE IS IN FAIR AGREEMENT OVER THE NEXT 12 HOURS WITH SPREADING AFTERWARDS AS MOST OF THE MODELS LOSE THE VORTEX DUE TO CYCLOLYSIS. THERE IS HIGH CONFIDENCE IN THE TRACK FORECAST. // NNNN