MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 18W (MALAKAS) WARNING NR 33// RMKS// 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TYPHOON 18W (MALAKAS), LOCATED APPROXIMATELY 159 NM SOUTH OF IWAKUNI, JAPAN, HAS TRACKED EAST-NORTHEASTWARD AT 17 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY DEPICTS A SYSTEM THAT HAS WEAKENED SLIGHTLY AFTER MAKING LANDFALL OVER SOUTHERN KYUSHU. THE POSITION IS BASED ON RECENT SATELLITE AND JMA RADAR FIXES FROM PGTW AND RJTD WITH GOOD CONFIDENCE. THE INITIAL INTENSITY IS ASSESSED AT 75 KNOTS AND IS BASED ON DVORAK ESTIMATES FROM PGTW AND RJTD REPORTING T4.5 (77 KNOTS). RECENT OBSERVATIONS FROM KANOYA AIR BASE SHOW THE SUSTAINED WINDS REACHED 56 KNOTS WITH GUSTS UP TO 95 KNOTS AT 191642Z, AS TY MALAKAS PASSED CLOSE TO THE SOUTH. UPPER-LEVEL ANALYSIS SHOWS INCREASING VALUES OF WIND SHEAR ASSOCIATED WITH THE WESTERLY JET AND A SHORTWAVE TROUGH MOVING IN FROM THE NORTHWEST. SEA SURFACE TEMPERATURES ARE FAVORABLE NEAR 28 CELSIUS. CURRENTLY TY MALAKAS IS TRAVELING EAST-NORTHEAST ALONG THE NORTHWESTERN PERIPHERY OF A DEEP-LAYERED SUBTROPICAL RIDGE LOCATED TO THE SOUTHWEST. 3. FORECAST REASONING. A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TY MALAKAS WILL CONTINUE TO TRACK NORTH-NORTHEAST UNDER THE INFLUENCE OF THE CURRENT STEERING RIDGE ALONG THE SHORELINE OF SOUTHERN JAPAN. THE CLOSE PROXIMITY TO LAND WILL DISRUPT THE LOW- LEVEL WIND FLOW THROUGHOUT THE FORECAST PERIOD. THIS IN CONJUNCTION WITH RISING SHEAR VALUES WILL SERVE TO WEAKEN THE SYSTEM. SSTS WILL REMAIN FAVORABLE THROUGH TAU 12, BUT AS TY MALAKAS PASSES THE KII PENINSULA SSTS WILL DROP CONSIDERABLY FURTHER CONTRIBUTING TO THE WEAKENING TREND. TY MALAKAS IS FORECAST TO DISSIPATE BY TAU 48. DYNAMIC MODEL GUIDANCE IS IN GOOD AGREEMENT THROUGH TAU 24, BUT START TO DIVERGE SOMEWHAT AFTER TY MALAKAS PASSES YOKOSUKA, JAPAN DUE TO A DRASTICALLY WEAKENED SYSTEM.// NNNN NNNN