WDPN31 PGTW 230300 MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 02W WARNING NR 06// RMKS/ 1. FOR METEOROLOGISTS. 2. 12 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 02W, LOCATED APPROXIMATELY 80 NM EAST OF YAP, HAS TRACKED WEST-NORTHWESTWARD AT 10 KNOTS OVER THE PAST 06 HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS CONVECTIVE BANDING WRAPPING INTO A LOW LEVEL CIRCULATION CENTER (LLCC) AND A 222259Z TRMM MICROWAVE IMAGE DEPICTS THE DEEP CONVECTION WRAPPING AROUND FROM THE SOUTHEAST TO SOUTHWEST QUADRANT. THE INITIAL POSITION IS BASED ON THIS MICROWAVE IMAGE. THE INITIAL INTENSITY IS BASED ON PGTW, RJTD, AND KNES DVORAK INTENSITY ESTIMATES OF 35 KNOTS. TS 02W REMAINS EQUATORWARD OF THE UPPER LEVEL SUBTROPICAL RIDGE (STR) AXIS WITH UPPER LEVEL DIVERGENCE PROVIDING GOOD RADIAL OUTFLOW, BUT ALSO MODERATE VERTICAL WIND SHEAR (VWS), WHICH IS LIMITING DEVELOPMENT. TS 02W IS CURRENTLY TRACKING NORTHWESTWARD ON THE SOUTHWESTERN PERIPHERY OF A LOW TO MID-LEVEL STEERING RIDGE (SR). 3. FORECAST REASONING A. THE FORECAST PHILOSOPHY HAS CHANGED SLIGHTLY SINCE THE PREVIOUS PROGNOSTIC REASONING BULLETIN. THE CURRENT FORECAST TRACK HAS SHIFTED MORE NORTHWARD, INDICATING A FASTER TURN CAUSED BY A GREATER WEAKENING IN THE SR. B. TS 02W IS FORECAST TO CONTINUE TRACKING NORTHWESTWARD ALONG THE SOUTHWESTERN PERIPHERY OF THE LOW TO MID-LEVEL SR FOR THE FIRST 72 HOURS. BY TAU 48, THE PASSAGE OF A MID-LATITUDE, UPPER LEVEL TROUGH WILL WEAKEN THE SR AND ALLOW TS 02W TO TURN NORTHWARD. INTENSITIES SHOULD SLOWLY INCREASE AS THE SYSTEM MOVES UNDER THE STR AXIS TO THE NORTH AND VWS DECREASES. TS 02W WILL ALSO SLOW AS THE SR WEAKENS. C. AFTER TAU 72, TC 02W WILL BEGIN TO WEAKEN DUE TO INCREASED VWS ASSOCIATED WITH THE TROUGH IN PARA 3.B. IT IS LIKELY THAT THE SYSTEM WILL DISSIPATE DUE TO SHEAR BEFORE RECURVATURE INTO THE WESTERLIES CAN OCCUR. THE NUMERICAL MODELS SHOW AN INCREASE IN RECURVATURE SCENARIOS INCLUDING THE ECMWF, GFS, AND GFDN MODLES. EGRR REMAINS A WESTERN OUTLIER BUT NOW TRACKS FARTHER NORTHWESTWARD VICE WESTWARD. HOWEVER, DUE TO HIGH VWS, TS 02W SHOULD DISSIPATE BEFORE A RECURVATURE SCENARIO IS POSSIBLE.// NNNN