MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 09W (BAVI) WARNING NR 007// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 09W (BAVI), LOCATED APPROXIMATELY 215 NM WEST OF KADENA AB, HAS TRACKED NORTHWARD AT 05 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A COMPACT SYSTEM WITH FLARING CONVECTION WRAPPING INTO A PARTIALLY EXPOSED LOW LEVEL CIRCULATION CENTER. THE CONVECTION HAS SLIGHTLY STRENGTHENED IN THE EASTERN SEMICIRCLE, BUT THE CONVECTION TO THE NORTHWEST REMAINS LIMITED DUE TO THE UPPER LEVEL CONVERGENCE POSITIONED TO THE NORTHWEST. THE INITIAL POSITION IS PLACED WITH GOOD CONFIDENCE BASED ON THE DEVELOPING MICROWAVE EYE IN THE 222259Z SSMIS 91GHZ PASS. THE INITIAL INTENSITY IS PLACED WITH GOOD CONFIDENCE, ALBEIT HEDGED ON THE HIGH SIDE OF MULTI-AGENCY DVORAK CURRENT INTENSITY ESTIMATES OF T3.0-3.5 (45-55 KNOTS), BASED ON THE AFOREMENTIONED MICROWAVE IMAGE. THE SYSTEM IS TRACKING GENERALLY NORTHWARD ALONG AN EXTENSION OF A SUBTROPICAL RIDGE (STR) POSITIONED TO THE SOUTHEAST. TS 09W IS CURRENTLY POSITIONED IN AN ENVIRONMENT FAVORABLE FOR FURTHER INTENSIFICATION WITH VERY WARM (30-31 CELSIUS) SEA SURFACE TEMPERATURES, LOW (05-10 KNOTS) 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 09W WILL CONTINUE TO TRACK GENERALLY NORTHEASTWARD AS IT ROUNDS THE STR POSITIONED TO THE SOUTHEAST, THROUGH TAU 24, BEFORE TURNING NORTHWARD AS THE STR REORIENTS. THE LOW VERTICAL WIND SHEAR AND VERY WARM SSTS WILL LIKELY ALLOW FOR FURTHER INTENSIFICATION TO 95 KTS BY TAU 48. WINDS MAY REACH ABOVE THE FORECASTED 100 KNOTS BETWEEN TAU 48 TO TAU 72, WHICH IS NOT DEPICTED IN THE FORECAST PRODUCTS. CROSS TRACK SPREAD HAS IMPROVED TO 60NM AT TAU 72. HOWEVER, INTENSITY GUIDANCE DURING THIS PERIOD SHOWS HIGH VARIANCE, LENDING POOR CONFIDENCE TO THE JTWC INTENSITY FORECAST. C. AFTER TAU 72, STRONG (20-25 KTS) VWS WILL BEGIN TO WEAKEN TS 09W DURING THE NORTHWARD TRACK TOWARDS NORTH KOREA. ADDITIONALLY, AROUND TAU 96, LAND INTERACTION WITH THE KOREAN PENINSULA AND COOL SEA SURFACE TEMPERATURES (24-24 DEGREES CELSIUS) WILL FURTHER WEAKEN TS 09W. THERE IS A FAIR DEGREE OF UNCERTAINTY IN MODEL SOLUTIONS DURING THIS PERIOD DUE TO THE TIMING OF THE SHORTWAVE TROUGH MOVEMENT, WITH A 220 NM SPREAD IN ALONG TRACK SPREAD BY TAU 96. THE SYSTEM IS EXPECTED TO MAKE LANDFALL AFTER TAU 96 AND RAPIDLY DETERIORATE AS IT MOVES INLAND DUE TO FRICTIONAL EFFECTS. THERE IS FAIR CONFIDENCE IN THE JTWC FORECAST TRACK. NNNN NNNN