MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 02W (SANBA) WARNING NR 19// RMKS// 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 02W (SANBA), LOCATED APPROXIMATELY 374 NM SOUTHEAST OF MANILA, PHILIPPINES, HAS TRACKED WESTWARD AT 11 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS AN ELONGATED AREA OF CONVECTION, MAINLY TO THE NORTH OF THE LOW LEVEL CIRCULATION CENTER (LLCC) ASSOCIATED WITH TS 02W. THE INITIAL POSITION IS BASED ON A 130613Z 85 GHZ MICROWAVE IMAGE, WHICH SHOWS WEAK BANDING WITH THE MAJORITY OF THE CONVECTION LOCATED TO THE NORTH OF THE LLCC. THE INITIAL INTENSITY OF 35 KNOTS IS HEDGED BETWEEN A 130155Z METOP-B ASCAT IMAGE WHICH SHOWS SOME 30 KNOT WIND BARBS AND A 121656Z SATCON ESTIMATE OF 47 KNOTS. UPPER LEVEL ANALYSIS SHOWS MODERATE (15 TO 20 KNOT) VERTICAL WIND SHEAR AND GOOD RADIAL OUTFLOW. SEA SURFACE TEMPERATURES AROUND THE CENTRAL PHILIPPINES ARE FAVORABLE, RANGING BETWEEN 27 TO 28 DEGREES CELSIUS. HOWEVER, TS 02W IS NOW INTERACTING WITH LAND WHICH IS LIMITING DEVELOPMENT. TS 02W IS TRACKING WESTWARD ALONG THE SOUTHWESTERN EDGE OF THE SUBTROPICAL RIDGE (STR) LOCATED TO THE NORTHEAST. 3. FORECAST REASONING. A. THERE IS NO CHANGE IN THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TS 02W WILL CONTINUE TRACKING WESTWARD BEFORE IT ROUNDS THE SOUTHWESTERN EDGE OF THE STR. CONTINUED LAND INTERACTION THROUGH TAU 12 WILL SLIGHTLY WEAKEN TS 02W TO 30 KNOTS. BEYOND TAU 24, TS 02W WILL TRACK OVER PALAWAN AND THEN INTO THE SOUTH CHINA SEA. THE STR WILL BEGIN TO STEER TS 02W ON A MORE NORTHWESTWARD TRACK BY TAU 36. INTERACTION WITH WARM WATERS IN THE SOUTHEAST PORTION OF THE SOUTH CHINA SEA WILL ALLOW FOR SLIGHT INTENSIFICATION TO 35 KNOTS BY TAU 36. AFTER TAU 48, TS 02W WILL MOVE INTO COOLER, UNFAVORABLE WATERS AND BEGIN TO DECREASE IN INTENSITY. TS 02W WILL CONTINUE TO TRACK NORTHWESTWARD AS IT REMAINS UNDER THE INFLUENCE OF THE STR TO THE NORTHEAST. C. IN THE EXTENDED FORECAST, BEYOND 72 HOURS, TS 02W WILL CONTINUE TO WEAKEN DUE TO UNFAVORABLE SEA SURFACE TEMPERATURES, NEAR 25 DEGREES CELSIUS. THE STR TO THE NORTHEAST WILL CONTINUE TO STEER TS 02W TOWARDS VIETNAM. TS 02W WILL WEAKEN TO 25 JUST PRIOR TO MAKING LANDFALL IN VIETNAM. AS TS 02W CONTINUES TO TRACK WESTWARD OVER LAND IT WILL CONTINUE TO WEAKEN AND BY TAU 120 WILL DISSIPATE WHILE OVER VIETNAM. NUMERICAL MODEL GUIDANCE IS IN GOOD AGREEMENT WITH THE EXCEPTION OF COAMPS, WHICH TRACKS TS 02W TO THE SOUTHWEST. OVERALL THERE IS HIGH CONFIDENCE IN THE JTWC FORECAST TRACK.// NNNN NNNN