WDPN31 PGTW 130900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 03W (THREE) WARNING NR 003// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 03W (THREE), LOCATED APPROXIMATELY 139 NM EAST OF DAVAO, PHILIPPINES, HAS TRACKED WESTWARD AT 11 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS AN EXPOSED LOW-LEVEL CIRCULATION (LLC) DISPLACED WEST OF AN ISOLATED DEEP CONVECTIVE BURST. HOWEVER, A 130721Z SSMI 91GHZ COLOR COMPOSITE MICROWAVE IMAGE AND A 130725Z GMI 37GHZ MICROWAVE IMAGE INDICATE SHALLOW BANDING WRAPPING INTO A COMPACT, WELL-DEFINED LLC, WHICH SUPPORTS THE INITIAL POSITION WITH GOOD CONFIDENCE. THE INITIAL INTENSITY REMAINS ASSESSED AT 35 KNOTS BASED ON A 130500Z ADT ESTIMATE OF 2.5 (35 KNOTS) AND A KNES DVORAK INTENSITY ESTIMATE OF T2.5 (35 KNOTS). ENVIRONMENTAL ANALYSIS INDICATES A MARGINALLY- FAVORABLE ENVIRONMENT WITH LOW VERTICAL WIND SHEAR (VWS), WEAK POLEWARD OUTFLOW AND WARM SST VALUES (29C). TS 03W IS TRACKING WESTWARD ALONG THE SOUTHERN PERIPHERY OF A LOW- TO MID-LEVEL SUBTROPICAL RIDGE (STR) ENTRENCHED TO THE NORTH. 3. FORECAST REASONING. A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TS 03W IS FORECAST TO TRACK WESTWARD TO WEST-NORTHWESTWARD THROUGH THE FORECAST PERIOD UNDER THE STEERING INFLUENCE OF THE STR POSITIONED TO THE NORTH. NUMERICAL MODEL GUIDANCE REMAINS IN FAIR AGREEMENT WITH A 90-135NM SPREAD IN SOLUTIONS AT TAU 48 TO TAU 72, LENDING MODERATE CONFIDENCE TO THE JTWC OFFICIAL FORECAST TRACK. TS 03W IS EXPECTED TO INTENSIFY SLIGHTLY TO 40 KNOTS BY TAU 12 BUT WILL WEAKEN AS IT TRACKS OVER MINDANAO FROM TAU 12 TO TAU 36. AFTER TAU 36, TS 03W WILL GRADUALLY DISSIPATE DUE TO INCREASING VWS (20-25 KNOTS) AND UPPER-LEVEL CONVERGENCE ASSOCIATED WITH A PERSISTENT UPPER-LEVEL TROUGH.// NNNN