WDPN32 PGTW 230300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 12W (AMPIL) WARNING NR 22// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM 12W (AMPIL), LOCATED APPROXIMATELY 373 NM WEST- SOUTHWEST OF KUNSAN AB, HAS TRACKED NORTHWESTWARD AT 10 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS A FULLY EXPOSED, SYMMETRIC CIRCULATION WITH DEEP CONVECTION LIMITED TO AN ISOLATED AREA NORTHEAST OF THE DISTINCT LOW LEVEL CIRCULATION CENTER (LLCC). THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE MSI IMAGERY. THE INITIAL INTENSITY OF 35 KNOTS IS BASED ON SYNOPTIC OBSERVATIONS FROM STATION 58040 (LOCATED ABOUT 40 NM NORTH OF THE LLCC) REPORTING WINDS OF 23 KNOTS FROM THE NORTHEAST. ENVIRONMENTAL ANALYSIS SHOWS TS 12W STILL HAS WEAK TO MODERATE POLEWARD OUTFLOW AND LOW VERTICAL WIND SHEAR (5 TO 10 KNOTS). TS 12W IS TRACKING NORTHWESTWARD ALONG THE WESTERN EDGE OF A SUBTROPICAL RIDGE (STR) LOCATED TO THE EAST. 3. FORECAST REASONING. A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TS 12W WILL CONTINUE TO TRACK NORTHWESTWARD ALONG THE PERIPHERY OF THE STR BEFORE ROUNDING THE RIDGE AXIS AND GRADUALLY TURNING NORTHEASTWARD BETWEEN TAU 12 AND TAU 36. ALTHOUGH TS 12W WILL BRIEFLY PASS OVER THE BOHAI SEA BETWEEN TAU 24 AND 36, LAND INTERACTION WILL CONTINUE TO AFFECT THE CYCLONE AND IT WILL WEAKEN TO 20 KNOTS BY TAU 48. OVERALL, DYNAMIC MODEL GUIDANCE IS IN GOOD AGREEMENT, THEREFORE, THERE IS HIGH CONFIDENCE IN THE JTWC FORECAST TRACK.// NNNN