MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 09W (BAVI) WARNING NR 006// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 09W (BAVI), LOCATED APPROXIMATELY 225 NM WEST OF KADENA AB, HAS TRACKED NORTHWARD AT 05 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A COMPACT SYSTEM WITH FLARING CONVECTION WRAPPING INTO A PARTIALLY EXPOSED LOW LEVEL CIRCULATION CENTER. THE CONVECTION IS STILL STRONG OVER THE SOUTHERN SEMICIRCLE, BUT THE CONVECTION TO THE NORTH REMAINS LIMITED DUE TO THE UPPER LEVEL CONVERGENCE POSITIONED TO THE NORTHWEST. THE INITIAL POSITION IS PLACED WITH GOOD CONFIDENCE BASED ON THE LOW LEVEL CIRCULATION FEATURES PRESENT IN THE EIR LOOP AND A 1755 ATMS 88GHZ MICROWAVE IMAGE. THE INITIAL INTENSITY IS ALSO PLACED WITH GOOD CONFIDENCE, HEDGED SLIGHTLY ABOVE MULTIAGENCY DVORAK CURRENT INTENSITY ESTIMATES OF T3.0 (45 KNOTS). THE SYSTEM IS TRACKING GENERALLY NORTHWARD ALONG AN EXTENSION OF A SUBTROPICAL RIDGE (STR) POSITIONED TO THE SOUTHEAST AND THROUGH AN ENVIRONMENT FAVORABLE FOR INTENSIFICATION WITH VERY WARM (30-31 CELSIUS) SEA SURFACE TEMPERATURES, LOW (10-15 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. THROUGH TAU 36, TS BAVI WILL CONTINUE TO TRACK GENERALLY NORTHEASTWARD AS IT ROUNDS THE STR POSITIONED TO THE SOUTHEAST BEFORE TURNING NORTH-NORTHWESTWARD AS THE STR REORIENTS. AN UPPER LEVEL TROUGH PASSING TO THE NORTH IS EXPECTED TO INTERACT WITH THE SYSTEM THROUGH THE NEXT 24 HOURS AND DIMINISH SLIGHTLY DIMINISH THE UPPER LEVEL OUTFLOW BETWEEN TAU 24 TO TAU 48. DESPITE THIS, LOW VERTICAL WIND SHEAR AND VERY WARM SSTS WILL LIKELY ALLOW FOR FURTHER, AND POSSIBLY RAPID, INTENSIFICATION TO 90 KTS BY TAU 48. HOWEVER, INTENSITY GUIDANCE DURING THIS PERIOD GIVES WIDE VARIANCE AND LENDS POOR CONFIDENCE TO THE JTWC INTENSITY FORECAST. C. AFTER TAU 72, DESPITE MODERATE TO STRONG (20-25 KTS) VWS, CONTINUED WARM SSTS AND IMPROVING UPPER LEVEL OUTFLOW WILL LEAD TO FURTHER INTENSIFICATION DURING THIS NORTHWARD TRACK AND ALLOW THE SYSTEM TO REACH A MAXIMUM INTENSITY OF 100 KTS BY TAU 72. THERE IS A FAIR DEGREE OF UNCERTAINTY IN MODEL SOLUTIONS DURING THIS PERIOD DUE TO THE TIMING OF THE SHORTWAVE TROUGH MOVEMENT, WITH A 290 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 ONLY FAIR CONFIDENCE IN THE JTWC FORECAST TRACK. NNNN NNNN