WDPN32 PGTW 060300 MSGID/GENADMIN/NAVPACMETOCCEN PEARL HARBOR HI/JTWC// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 15W WARNING NR 02// RMKS/ 1. FOR METEOROLOGISTS. 2. PROGNOSTIC REASONING FOR 060000Z TO 110000Z SEP 2005. A. TROPICAL STORM (TS) 15W, LOCATED APPROXIMATELY 50 NM NORTH OF YAP, HAS TRACKED NORTHWESTWARD AT 13 KNOTS OVER THE PAST SIX HOURS. B. TS 15W IS FORECAST TO TRACK NORTHWESTWARD ALONG THE SOUTH- WESTERN PERIPHERY OF THE LOW TO MID-LEVEL STEERING RIDGE ANCHORED TO THE SOUTHEAST OF JAPAN. THE AVAILABLE DYNAMIC AIDS CONSISTING OF NOGAPS, COAMPS, AFWA MM5, NCEP GFS, UKMET EGRR AND WBAR ARE IN FAIR AGREEMENT WITH THIS SCENARIO. WBAR FORECASTS A STRONGER STEER- ING RIDGE AND THUS A MORE EQUATORWARD TRACK THAN THE OTHER AIDS. THIS FORECAST IS BASED ON A CONSENSUS OF ALL AVAILABLE DYNAMIC AIDS. C. ANIMATED SATELLITE IMAGERY SHOWS CONTINUED DEVELOPMENT OF THE DEEP CONVECTION ASSOCIATED WITH TS 15W. TS 15W IS FORECAST TO INTENSIFY AT A CLIMATOLOGICAL RATE THROUGH TAU 36 IN AN ENVIRONMENT OF FAVORABLE DIFFLUENCE AND LOW VERTICAL WIND SHEAR. TS 15W IS FORE- CAST TO INTENSIFY AT A SLOWER RATE AFTER TAU 36 DUE TO A DECREASE IN AVAILABLE MID-LEVEL MOISTURE. RAPID INTENSIFICATION OF THIS SYSTEM IS POSSIBLE IF AN OUTFLOW CHANNEL DEVELOPS OR IF RADIAL OUTFLOW IMPROVES. D. CURRENT WIND RADII ARE BASED ON SURFACE OBSERVATIONS AND CLIMATOLOGY. FORECAST WIND RADII ARE BASED ON CLIMATOLOGY FOR AN AVERAGE SIZED SYSTEM. E. IN THE EXTENDED FORECAST, TS 15W WILL CONTINUE TO TRACK ALONG THE SOUTHWESTERN PERIPHERY OF THE STEERING RIDGE ANCHORED TO THE SOUTHEAST OF JAPAN. THE INTENSITY OF TS 15W IS FORECAST TO REMAIN CONSTANT AFTER TAU 96 AS THE SYSTEM APPROACHES LAND AND THE LOW LEVEL INFLOW IS DISRUPTED BY THE TERRAIN OF TAIWAN. 3. FORECAST TEAM: BRAVO//