MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 24W (SARIKA) WARNING NR 22// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TYPHOON 24W (SARIKA), LOCATED APPROXIMATELY 233 NM NORTHEAST OF DA NANG, VIETNAM, HAS TRACKED WEST-NORTHWESTWARD AT 09 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY DEPICTS A SYSTEM BECOMING INCREASINGLY DISORGANIZED AND HAS LOST ITS RAGGED EYE FEATURE OVER THE LAST SIX HOURS AS IT APPROACHES HAINAN. A 171646Z AMSR2 91 GHZ IMAGE SHOWS A BROAD LOW LEVEL CIRCULATION CENTER, GIVING FAIR CONFIDENCE TO THE INITIAL POSITION, WITH A DEEP BAND OF CONVECTION WRAPPING IN FROM THE WEST AND SOUTHEAST. THE CURRENT INTENSITY IS ASSESSED AT 75 KNOTS AND IS BASED ON THE WEAKENING CONVECTIVE STRUCTURE COMBINED WITH CURRENT INTENSITY DVORAK ESTIMATES AT T4.5 (77 KNOTS). UPPER-LEVEL ANALYSIS SHOWS GOOD RADIAL OUTFLOW TAPPING INTO A PASSING SHORTWAVE TROUGH TO THE NORTHWEST AND DOMINANT EASTERLY FLOW ON THE EQUATORWARD SIDE. SEA SURFACE TEMPERATURES ARE ALSO FAVORABLE NEAR 29 CELSIUS. THE RECENT DROP IN INTENSITY AND CONVECTIVE STRUCTURE IS ATTRIBUTED TO LAND INTERACTION WITH HAINAN DESPITE ALL OTHER VARIABLES BEING FAVORABLE. CURRENTLY TY SARIKA IS TRACKING NORTHWEST ALONG THE PERIPHERY OF A DEEP-LAYERED SUBTROPICAL RIDGE TO THE NORTHEAST.3. FORECAST REASONING. A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING BULLETIN. B. TY SARIKA WILL CONTINUE TO TRACK NORTHWEST GUIDED BY THE CURRENT STEERING RIDGE MAKING LANDFALL OVER HAINAN IN THE NEXT 6 TO 12 HOURS AND WEAKENING SIGNIFICANTLY. THE TRACK WILL CONTINUE OVER THE GULF OF TONKIN MAINTAINING TROPICAL STORM STRENGTH BEFORE MAKING LANDFALL NEAR THE VIETNAM-CHINA BORDER AND THEN TURNING NORTHWARD AS IT ROUNDS THE STEERING RIDGE AXIS. AVAILABLE MODEL GUIDANCE IS IN VERY GOOD AGREEMENT AS THE SYSTEM TRACKS OVER HAINAN AND INTO VIETNAM, BUT STARTS TO DIVERGE AS IT TRACKS FURTHER INLAND ROUNDING THE RIDGE AXIS. OVERALL THERE IS HIGH CONFIDENCE IN THE FORECAST TRACK.// NNNN NNNN