WDPN31 PGTW 040300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 05W (NANMADOL) WARNING NR 09// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 05W (NANMADOL), LOCATED APPROXIMATELY 35 NM EAST-SOUTHEAST OF SASEBO, JAPAN, HAS TRACKED NORTHEASTWARD AT 25 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY SHOWS A MORE RAPID WEAKENING TREND, INDICATED BY WARMING CONVECTIVE TOPS, AS THE SYSTEM MADE LANDFALL OVER KYUSHU. THE INITIAL POSITION IS BASED ON A WELL-DEFINED CIRCULATION FEATURE ON A JMA COMPOSITE REFLECTIVITY RADAR LOOP WITH HIGH CONFIDENCE. THE INITIAL INTENSITY OF 40 KNOTS IS EXTRAPOLATED FROM NEARBY SURFACE OBSERVATIONS, INCLUDING ONE FROM UNZENDAKE, 6 NM FROM STORM CENTER. UPPER-LEVEL ANALYSIS INDICATES ROBUST POLEWARD OUTFLOW ENHANCED BY THE MIDLATITUDE WESTERLIES TO THE NORTH. TS 05W IS ACCELERATING ALONG THE POLEWARD SIDE OF THE DEEP SUBTROPICAL RIDGE (STR). 3. FORECAST REASONING. A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TS NANMADOL IS FORECAST TO CONTINUE ACCELERATING NORTHEASTWARD AND IS NOW INTERACTING WITH THE MIDLATITUDE WESTERLY FLOW. THE SYSTEM WILL ALSO CONTINUE TO RAPIDLY WEAKEN DUE TO STRONG VERTICAL WIND SHEAR AND AS IT TRACKS OVER THE RUGGED TERRAIN OF KYUSHU, SHIKOKU, AND HONSHU. AFTER TAU 12, TS 05W WILL UNDERGO EXTRA-TROPICAL TRANSITION (ETT, COMPLETING ETT BY TAU 24. THE DYNAMIC AIDS REMAIN IN VERY TIGHT AGREEMENT LENDING HIGH CONFIDENCE TO THE FORECAST TRACK.// NNNN