MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 27W (KALMAEGI) WARNING NR 31// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 27W (KALMAEGI), LOCATED APPROXIMATELY 103 NM NORTH OF MANILA, PHILIPPINES, HAS TRACKED SOUTHWESTWARD AT 13 KNOTS OVER THE PAST SIX HOURS. THERE IS FAIR CONFIDENCE IN THE INITIAL POSITION BASED ON A POORLY DEFINED CIRCULATION CENTER WITH CONVECTION SHEARED TO THE NORTH AS SEEN IN ANIMATED MULTISPECTRAL SATELLITE IMAGERY. THE 40 KNOT INITIAL INTENSITY REFLECTS THE WEAKENED CONVECTIVE STRUCTURE AND IS CONSISTENT WITH AN EARLIER 200134Z METOP-C ASCAT PASS SHOWING 35-40 KNOT WINDS OFF THE NORTHWEST COAST OF LUZON IN THE SOUTH CHINA SEA. STRONG (25-30 KT) NORTHERLY VERTICAL WIND SHEAR (VWS) AND LAND INTERACTION ARE OVERCOMING GOOD POLEWARD OUTFLOW TO MAKE THE ENVIRONMENT UNFAVORABLE. TS 27W IS TRACKING ALONG THE SOUTHEASTERN PERIPHERY OF A SUBTROPICAL RIDGE CENTERED OVER THE SOUTH CHINA SEA (SCS). 3. FORECAST REASONING. A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY FROM THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. BEFORE DISSIPATING AROUND TAU 48, TS 27W WILL TRACK SOUTHWESTWARD ALONG THE AFOREMENTIONED STR. DESPITE MOVING OVER THE SCS BEFORE TAU 12, THE ENVIRONMENT WILL REMAIN UNFAVORABLE WITH CONVERGENCE ALOFT. STEADY WEAKENING WILL CONTINUE UNTIL DISSIPATION. THERE IS STRONG CROSS TRACK AGREEMENT AND FAIR ALONG-TRACK AGREEMENT IN NUMERICAL MODEL GUIDANCE, LENDING MODERATE CONFIDENCE IN THE JTWC FORECAST TRACK.// NNNN NNNN