MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 11W (HAISHEN) WARNING NR 027// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM 11W (HAISHEN), LOCATED APPROXIMATELY 26 NM NORTH- NORTHWEST OF BUSAN, SOUTH KOREA, HAS TRACKED NORTHWARD AT 23 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY AND A COMPOSITE RADAR LOOP INDICATE THE SYSTEM HAS RAPIDLY ERODED AFTER IT MADE LANDFALL AS EVIDENCED BY THE UNRAVELING AND COLLAPSING OF CONVECTIVE BANDS. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE CIRCULATION FEATURE IN THE RADAR LOOP AND TRIANGULATION OF NUMEROUS WIND OBSERVATIONS OVER LAND. THE INITIAL INTENSITY OF 45 KTS IS EXTRAPOLATED FROM AGENCY DVORAK ESTIMATES PRIOR TO LANDFALL AND FROM THE SURFACE WIND OBSERVATIONS. UPPER LEVEL ANALYSIS INDICATES A ROBUST POLEWARD OUTFLOW THAT IS OFFSET BY STRONG (30-KT+) VERTICAL WIND SHEAR. ALSO, THE RUGGED MOUNTAINOUS TERRAIN IS GREATLY CONTRIBUTING TO THE RAPID EROSION OF THE SYSTEM FROM BELOW. THE CYCLONE IS TRACKING ALONG THE WESTERN PERIPHERY OF THE SUBTROPICAL RIDGE (STR) TO THE EAST. 3. FORECAST REASONING. A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM THE LAST PROGNOSTIC REASONING MESSAGE. B. TS HAISHEN WILL CONTINUE TO TRACK NORTHWARD THROUGHOUT THE FORECAST PERIOD UNDER THE STR, MOMENTARILY EXIT INTO THE SEA OF JAPAN SHORTLY AFTER TAU 06, THEN MAKE A SECONDARY AND FINAL LANDFALL INTO NORTH KOREA BY TAU 12 BEFORE CROSSING INTO MANCHURIA. THE HOSTILE ENVIRONMENT, WITH THE ADDITION OF FRICTIONAL EFFECTS OF THE RUGGED MOUNTAIN RANGES OF THE KOREAN PENINSULA WILL RAPIDLY ERODE AND DISPERSE THE CONVECTIVE BANDS. CONCURRENTLY, THE SYSTEM HAS ENTERED THE BAROCLINIC ZONE AND BEGUN EXTRA-TROPICAL TRANSITION AND WILL TRANSFORM INTO A 30-KNOT COLD-CORE LOW BY TAU 12. NUMERICAL MODELS REMAIN IN TIGHT AGREEMENT WITH THE EXCEPTION OF AFUM WHICH CONTINUES TO BE AN EXTREME RIGHT-OF-TRACK OUTLIER AND DRIVES THE VORTEX INTO THE STR. THERE IS HIGH CONFIDENCE IN THE JTWC FORECAST TRACK THAT IS LAID LEFT OF THE MODEL CONSENSUS TO OFFSET AFUM.// NNNN NNNN