MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 10W (LINFA) WARNING NR 17// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 10W (LINFA), LOCATED APPROXIMATELY 268 NM NORTH-NORTHWEST OF MANILA, PHILIPPINES, HAS TRACKED NORTH- NORTHWESTWARD AT 06 KNOTS OVER THE PAST SIX HOURS. RECENT MSI DEPICTS A FULLY-EXPOSED WELL-STRUCTURED LLCC WITH THE DEEP CONVECTION DISPLACED TO THE SOUTHWEST. THE CURRENT POSITION IS BASED ON THE EXPOSED FEATURE WITH HIGH CONFIDENCE. THE CURRENT INTENSITY HAS LOWERED TO 40 KNOTS BASED ON THE WEAKENED STRUCTURE AND DECREASED DVORAK INTENSITY ESTIMATES FROM ALL REPORTING AGENCIES. UPPER-LEVEL ANALYSIS INDICATES THE SYSTEM IS LOCATED IN AN AREA OF MODERATE TO HIGH (20 TO 30 KNOT) NORTHEASTERLY VWS PARTIALLY OFFSET BY GOOD DIFFLUENT OUTFLOW. TS 10W IS CURRENTLY TRACKING UNDER THE STEERING INFLUENCE OF THE LOW- TO MID-LEVEL STR TO THE EAST. 3. FORECAST REASONING. A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TS 10W WILL CONTINUE TO TRACK SLOWLY POLEWARD UNDER THE INFLUENCE OF THE STEERING STR. MARGINALLY FAVORABLE CONDITIONS ARE EXPECTED, LIMITING INTENSIFICATION AND REACHING TO A PEAK INTENSITY OF 55 KNOTS BY TAU 36. C. IN THE EXTENDED TAUS, CONTINUED SLOW MOVEMENT AND A WEAKENING TREND ARE EXPECTED AS THE SYSTEM TRACKS NORTHWARD OVER TAIWAN. DYNAMIC MODEL GUIDANCE HAS SLIGHTLY IMPROVED AND IS IN GOOD AGREEMENT. HOWEVER, DUE TO DIFFERENCES IN TRACK SPEEDS AMONG AVAILABLE TRACKERS, COMPLEX STEERING ENVIRONMENT, AND POSSIBLE WEAK DIRECT CYCLONE INTERACTION WITH TS 09W, THE OVERALL JTWC FORECAST CONFIDENCE LEVEL REMAINS LOW.// NNNN NNNN