MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 08W (EIGHT) WARNING NR 001// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL DEPRESSION (TD) 08W (EIGHT), LOCATED APPROXIMATELY 285 NM EAST-SOUTHEAST OF HONG KONG, HAS TRACKED WESTWARD AT 10 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS FRAGMENTED CONVECTIVE BANDING WRAPPING INTO A POORLY- DEFINED LOW-LEVEL CIRCULATION CENTER. THE INITIAL POSITION WAS PLACED WITH POOR CONFIDENCE BASED ON THE EIR LOOP AND EXTRAPOLATION. THE INITIAL 25KT INTENSITY IS BASED ON THE PGTW DVORAK ESTIMATE OF T1.5 (35 KTS). THE ENVIRONMENT, WITH LIGHT VERTICAL WIND SHEAR AND FAIR EQUATORWARD OUTFLOW AND WARM 31C SSTS IN THE SOUTH CHINA SEA, IS VERY FAVORABLE FOR FURTHER DEVELOPMENT. THE CYCLONE IS TRACKING ALONG THE SOUTHERN PERIPHERY OF A SUBTROPICAL RIDGE (STR) TO THE NORTH. 3. FORECAST REASONING. A. THIS IS THE INITIAL PROGNOSTIC REASONING MESSAGE FOR THIS SYSTEM AND SETS THE FORECAST PHILOSOPHY. B. TD 08W IS EXPECTED TO TRACK MORE WEST-NORTHWESTWARD ALONG THE WESTERN SECTION OF THE STR, MAKING LANDFALL SHORTLY AFTER TAU 36 NEAR YANGJIANG, CHINA. THE FAVORABLE ENVIRONMENT WILL FUEL INTENSIFICATION TO A PEAK OF 45KTS JUST BEFORE LANDFALL. AFTERWARD, THE RUGGED CHINESE TERRAIN, IN ADDITION TO INCREASING VWS, WILL RAPIDLY ERODE THE SYSTEM TO DISSIPATION BY TAU 72, OR SOONER. NUMERICAL MODELS ARE IN GOOD AGREEMENT FOR A FIRST WARNING WITH GRADUAL SPREADING TO 300NM BY TAU 72. HOWEVER, THERE IS LOW CONFIDENCE IN THIS INITIAL JTWC WARNING THAT IS LAID SLIGHTLY LEFT OF CONW TO OFFSET NVGM, THE SOLE OUTLIER ON THE RIGHT MARGIN OF THE ENVELOPE, GIVEN THE FORMATIVE NATURE OF THE CYCLONE.// NNNN NNNN