MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 09W (BAVI) WARNING NR 004// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 09W (BAVI), LOCATED APPROXIMATELY 282 NM WEST- SOUTHWEST OF KADENA AB, OKINAWA, HAS TRACKED NORTH-NORTHEASTWARD AT 09 KNOTS (KTS) OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A WELL ORGANIZED, COMPACT SYSTEM WITH SUSTAINED CONVECTION AND FORMATIVE BANDING WRAPPING INTO THE CENTER OF A CONSOLIDATING LOW LEVEL CIRCULATION. THE INITIAL POSITION IS PLACED WITH FAIR CONFIDENCE BASED ON THE CIRCULATION EVIDENT IN THE COMPOSITE RADAR AND MSI LOOPS. THE INITIAL INTENSITY OF 45 KTS IS PLACED WITH HIGH CONFIDENCE AND IS HEDGED SLIGHTLY HIGHER THAN MULTIAGENCY DVORAK CURRENT INTENSITY ESTIMATES OF T2.0 (RCTP, 30 KTS) AND T2.5 (PGTW AND RJTD, 35 KTS) BASED ON OBSERVATIONS FROM ISHIGAKI JIMA OF 45 KTS (10 MINUTE AVERAGE) AND A 220526Z SATELLITE CONSENSUS INTENSITY ESTIMATE OF 42 KTS. THE SYSTEM IS TRACKING GENERALLY NORTH-NORTHEASTWARD ALONG AN EXTENSION OF A SUBTROPICAL RIDGE (STR) POSITIONED TO THE SOUTHEAST AND THROUGH AN ENVIRONMENT FAVORABLE FOR RAPID INTENSIFICATION WITH VERY WARM (30-31 CELSIUS) SEA SURFACE TEMPERATURES, LOW (5-10 KTS) VERTICAL WIND SHEAR AND WELL ESTABLISHED EQUATORWARD OUTFLOW IN THE UPPER LEVELS. 3. FORECAST REASONING. A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TS BAVI WILL CONTINUE TO TRACK GENERALLY NORTHEASTWARD AS IT ROUNDS THE STR POSITIONED TO THE SOUTHEAST. AN UPPER LEVEL TROUGH POSITIONED TO THE NORTH IS EXPECTED TO INTERACT WITH THE SYSTEM THROUGH THE NEXT 24 HOURS AND ENHANCE UPPER LEVEL POLEWARD OUTFLOW. THIS ENHANCED OUTFLOW, ALONG WITH CONTINUED LOW VERTICAL WIND SHEAR AND VERY WARM SSTS WILL ALLOW FOR FURTHER, AND POSSIBLY RAPID, INTENSIFICATION TO 70 KTS BY TAU 24 AND TO 80 KTS BY TAU 36. DURING THIS TIME, THE INCOMING SHORTWAVE TROUGH WILL CAUSE A REORIENTATION AND EROSION OF THE STEERING STR. AS A RESULT, TS BAVI WILL SLOW AND BEGIN TRACKING NORTHWARD ALONG THE WESTERN PERIPHERY OF A STR POSITIONED TO THE EAST STARTING AT TAU 48. CONTINUED WARM SSTS AND MODERATE (20-25 KTS) VWS WILL LEAD TO FURTHER INTENSIFICATION DURING THIS NORTHWARD TRACK AND ALLOW THE SYSTEM TO REACH 100 KTS BY TAU 72. THERE IS A FAIR DEGREE OF UNCERTAINTY IN MODEL SOLUTIONS DURING THIS PERIOD DUE TO THE TIMING OF THE INCOMING SHORTWAVE TROUGH, WITH A 132 NM SPREAD IN ACROSS TRACK SOLUTIONS BY TAU 48. THIS SPREAD IN SOLUTIONS LENDS ONLY FAIR CONFIDENCE TO THE INITIAL PORTION (TAU 0-72) OF THE JTWC FORECAST TRACK. C. IN THE EXTENDED FORECAST, TS BAVI WILL CONTINUE TO TRACK ALONG THE WESTERN PERIPHERY OF THE STEERING RIDGE WHICH WILL CONTINUE TO BUILD OVER HONSHU AFTER THE UPPER LEVEL SHORTWAVE TROUGH PROPAGATES EASTWARD. THE CONTINUED FAVORABLE ENVIRONMENT OF WARM SSTS AND LOW VWS WILL ALLOW THE SYSTEM TO FURTHER INTENSIFY TO A PEAK INTENSITY OF 105 KTS BY TAU 96. AS THE SYSTEM CONTINUES TO TRACK ALONG THE STEERING RIDGE, IT WILL MAKE LANDFALL OVER SOUTH KOREA AFTER TAU 96 AND BEGIN TO WEAKEN DUE TO THE FRICTIONAL EFFECTS OF LAND INTERACTION. GLOBAL MODEL SOLUTIONS REMAIN IN FAIR AGREEMENT WITH A 233 NM ACROSS TRACK SPREAD AT TAU 120. THIS SPREAD IN MODEL SOLUTIONS LENDS OVERALL FAIR CONFIDENCE IN THE JTWC FORECAST TRACK.// NNNN NNNN