MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 15W (LINGLING) WARNING NR 02// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 15W (LINGLING), LOCATED APPROXIMATELY 601 NM SOUTH-SOUTHWEST OF KADENA AB, HAS TRACKED NORTH-NORTHWESTWARD AT 10 KNOTS (KTS) OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY REVEALS A PARTIALLY EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC) AND WIDESPREAD, FLARING DEEP CONVECTION. A 020528Z AMSR2 89 GHZ MICROWAVE IMAGE PROVIDES HIGH CONFIDENCE IN THE INITIAL POSITION. THE INITIAL INTENSITY OF 35 KNOTS IS BASED ON A DVORAK CURRENT INTENSITY ESTIMATE OF T2.5 (35 KTS) FROM PGTW. THE ENVIRONMENT IS FAVORABLE OVERALL WITH MODERATE (15-20 KT) VERTICAL WIND SHEAR (VWS), WARM SEA SURFACE TEMPERATURE (29-30 CELSIUS), AND GOOD POLEWARD AND EQUATOR OUTFLOW CHANNELS. TS 15W IS TRACKING ALONG THE SOUTHWESTERN PERIPHERY OF A SUBTROPICAL RIDGE (STR). 3. FORECAST REASONING. A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. OVER THE NEXT 36 HOURS, TS 15W WILL CONTINUE TRACKING GENERALLY POLEWARD ALONG THE WESTERN PERIPHERY OF THE STR. AROUND TAU 48, AN APPROACHING MID-LATITUDE TROUGH WILL SLIGHTLY REORIENT THE STR AND CAUSE A SLIGHT SHIFT IN THE TRACK, ALTHOUGH IT WILL CONTINUE TO TRACK GENERALLY POLEWARD. THE ENVIRONMENT WILL REMAIN FAVORABLE THROUGH TAU 72, ALLOWING FOR STEADY INTENSIFICATION TO 70 KTS. NUMERICAL MODEL GUIDANCE FOLLOWS THE SAME GENERAL TRACK AS THE JTWC FORECAST, LENDING TO FAIR CONFIDENCE FOR THIS PORTION OF THE FORECAST. C. AFTER TAU 72, THE POLEWARD TRACK WILL CONTINUE UNDER THE INFLUENCE OF THE STR AND MID-LATITUDE TROUGH. BY TAU 120, TS 15W WILL BE OVER THE RELATIVELY COOL WATERS OF THE YELLOW SEA. COOLER SST AND HIGH VWS WILL MAKE THE ENVIRONMENT UNFAVORABLE AND STEADY WEAKENING IS EXPECTED AS TS 15W APPROACHES THE KOREAN PENINSULA. DYNAMIC MODEL TRACK GUIDANCE IS IN POOR AGREEMENT IN THE EXTENDED PERIOD, PRIMARILY DUE TO LARGE DIFFERENCES IN ALONG-TRACK SPEED. THE OFFICIAL TRACK FORECAST IS SLIGHTLY SLOWER THAN THE CONSENSUS, CLOSER TO THE ECMWF SOLUTION BUT CONFIDENCE IS LOW DUE TO THE HIGH UNCERTAINTY IN THE TRACK SPEED.// NNNN NNNN