MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR SUPER TYPHOON 10W (LEKIMA) WARNING NR 18// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUPER TYPHOON (STY) 10W (LEKIMA), LOCATED APPROXIMATELY 214 NM SOUTHWEST OF KADENA AB, OKINAWA, JAPAN, HAS TRACKED NORTH-NORTHWESTWARD AT 10 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS THE SYSTEM CONTINUED TO RAPIDLY INTENSIFY AS EVIDENCED BY A TIGHTLY COMPACT CENTRAL CONVECTION WITH ANNULAR CHARACTERISTICS AND A SHARPLY OUTLINED 8-NM EYE. THE TRAILING RAIN BANDS TO THE SOUTHWEST HAVE DETACHED. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE EYE FEATURE THAT LINED UP PERFECTLY WITH A WELL-DEFINED MICROWAVE PINHOLE EYE IN THE 080421Z GPM 36GHZ COLORIZED IMAGE. THE INITIAL INTENSITY OF 130KTS IS BASED ON THE DVORAK ESTIMATES OF T6.5/127KTS FROM PGTW AND RJTD AND REFLECTS RAPID INTENSIFICATION (RI) OVER THE PAST SIX HOURS. ENVIRONMENTAL ANALYSIS INDICATES EXCELLENT RADIAL OUTFLOW, LOW VERTICAL WIND SHEAR (VWS) AND WARM SST (30C). STY 10W IS TRACKING ALONG THE SOUTHWEST PERIPHERY OF A SUBTROPICAL RIDGE (STR) TO THE NORTHEAST. 3. FORECAST REASONING. A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TY 10W WILL CONTINUE ON ITS CURRENT NORTHWESTWARD TRACK UNDER THE INFLUENCE OF THE STR, MOVING MORE NORTHWARD AFTER TAU 36 AS THE STR REORIENTS IN A NORTH-SOUTH CONFIGURATION TO THE EAST. BY TAU 48, THE SYSTEM WILL REACH THE EAST COAST OF CHINA NEAR TAIZHOU. THE FAVORABLE CONDITIONS WILL SUSTAIN THE CURRENT STY UP TO TAU 12. AFTERWARD, INCREASING VWS AND LAND INTERACTION WILL WEAKEN IT TO 60 KNOTS BY TAU 72, SHORTLY AFTER TRACKING OVER SHANGHAI. NUMERICAL MODEL GUIDANCE IS IN GOOD AGREEMENT WITH A 100NM SPREAD IN SOLUTIONS AT TAU 72, LENDING FAIR CONFIDENCE IN THIS PORTION OF THE JTWC FORECAST TRACK. C. AFTER TAU 72, STY LEKIMA WILL TURN MORE NORTH-NORTHWESTWARD AND FURTHER INLAND ALONG THE WESTERN PERIPHERY OF THE BUILDING STR. RAPID WEAKENING IS EXPECTED PRIMARILY DUE TO LAND INTERACTION, LEADING TO DISSIPATION BY TAU 120. NUMERICAL MODELS SIGNIFICANTLY DIVERGE IN ALL DIRECTIONS AS THEY LOSE THE WEAK VORTEX; THEREFORE, THERE IS LOW CONFIDENCE IN THE EXTENDED PORTION OF THE JTWC FORECAST TRACK.// NNNN NNNN