WDPN31 PGTW 231500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 22W (TRAMI) WARNING NR 013// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 16.9N 122.9E INITIAL INTENSITY: 45 KTS GEOGRAPHIC REFERENCE: 176 NM NORTHEAST OF MANILA, PHILIPPINES MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 08 KTS SIGNIFICANT WAVE HEIGHT: 30 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: MARGINALLY FAVORABLE ENVIRONMENTAL CONDITIONS CONTINUE TO HINDER THE DEVELOPMENT OF TROPICAL STORM (TS) 22W. UPPER-LEVEL ANALYSIS DEPICTS A POINT SOURCE EAST OF THE SYSTEM CENTER, WHICH IS PRODUCING VIGOROUS WESTWARD OUTFLOW AND PERSISTENT DEEP CONVECTION OVER THE WESTERN QUADRANT. HOWEVER, A BROAD UPPER-LEVEL TROUGH OVER THE NORTHEASTERN QUADRANT AND THE ASSOCIATED CONVERGENCE IS SUPPRESSING CONVECTIVE DEVELOPMENT. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY REVEALS DEEP CONVECTION BUILDING OVER THE SOUTHWESTERN QUADRANT OF A BROAD, PARTIALLY EXPOSED LOW-LEVEL CIRCULATION (LLC). A 231003Z SSMIS 91GHZ COLOR COMPOSITE MICROWAVE IMAGE SUPPORTS THE INITIAL POSITION WITH HIGH CONFIDENCE AND SHOWS CONVECTIVE BANDING PRIMARILY OVER THE SOUTHERN SEMICIRCLE WRAPPING INTO THE SOUTHERN QUADRANT OF THE DEFINED LOW-LEVEL CIRCULATION CENTER. A 231000Z RCM-3 SAR IMAGE SHOWS A VERY BROAD CORE OF WEAK WINDS WITH UNREALISTICALLY HIGH MAXIMUM WINDS OF 60-65 KNOTS. THE INITIAL INTENSITY OF 45 KTS IS ASSESSED WITH HIGH CONFIDENCE BASED ON CONCURRENT DVORAK CURRENT INTENSITY ESTIMATES OF T3.0 (45 KNOTS) FROM ALL AGENCIES. INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK CURRENT STEERING MECHANISM: DEEP-LAYERED SUBTROPICAL RIDGE (STR) POSITIONED TO THE NORTHEAST. AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T3.0 - 45 KTS RJTD: T3.0 - 45 KTS RCTP: T3.0 - 45 KTS DEMS: T3.0 - 45 KTS CIMSS SATCON: 54 KTS AT 231017Z CIMSS ADT: 41 KTS AT 231130Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE VWS: 15-20 KTS SST: 29-30 CELSIUS OUTFLOW: MODERATE WESTWARD ANALYSIS CONFIDENCE: INITIAL POSITION: HIGH INITIAL INTENSITY: HIGH INITIAL WIND RADII: LOW 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TROPICAL STORM (TS) 22W IS FORECAST TO TRACK WEST-NORTHWESTWARD THROUGH TAU 12 ALONG THE SOUTHWESTERN PERIPHERY OF THE STR, TOWARD A BREAK IN THE STR PRODUCED BY A MIDLATITUDE SHORTWAVE TROUGH DIGGING INTO THE EAST CHINA SEA. AFTER TAU 12, THE STR WILL REBUILD TO THE NORTH TURNING THE SYSTEM ONTO A MORE WESTWARD TRAJECTORY. THE SYSTEM WILL MAKE LANDFALL NEAR TAU 03, WITH SIGNIFICANT WEAKENING COMMENCING. AFTER TAU 12, TS 22W WILL WEAKEN AND DECOUPLE WHILE CROSSING THE RUGGED TERRAIN OF LUZON, WITH A LIKELY LEESIDE JUMP. THIS WILL RESULT IN AN APPARENT DIP IN THE FORECAST TRACK AS A NEW PRESSURE CENTER FORMS AND STRENGTHENS OFF THE WEST COAST OF LUZON NEAR TAU 24. AFTER TAU 36, THE SYSTEM WILL RESUME A WESTWARD TRACK UNDER THE STR TO THE NORTH WITH STEADY INTENSIFICATION TO ABOUT 60 KNOTS BY TAU 72. AFTER TAU 72, TS 22W WILL SLOW AND STALL AS A SUBTROPICAL RIDGE BUILDS TO THE WEST OF THE SYSTEM INDUCED BY THE DEVELOPING TROPICAL CYCLONE IN THE BAY OF BENGAL (TC 03B). MODEL DISCUSSION: DETERMINISTIC MODEL GUIDANCE REMAINS IN GOOD AGREEMENT THROUGH TAU 72, WITH A 80NM TO 85NM CROSS-TRACK SPREAD FROM TAU 48 TO TAU 72. AFTER TAU 72, THE GUIDANCE DIVERGES SIGNIFICANTLY WITH MANY MODELS INDICATING A QUASISTATIONARY TRACK MOTION AND STALL EAST OF VIETNAM. GFS HAS SHIFTED ITS TRACK JUST OFF THE COAST OF CENTRAL VIETNAM BUT STILL DISSIPATES THE SYSTEM BY TAU 120. THE 230000Z ECMWF ENSEMBLE (EPS) AND THE 230600Z GFS ENSEMBLE (GEFS) SHOW THE LARGE MAJORITY OF SOLUTIONS STALLING EAST OF VIETNAM WHILE MAINTAINING A MINIMAL TROPICAL STORM STRENGTH SYSTEM. RELIABLE INTENSITY GUIDANCE SHOWS A PEAK INTENSITY NEAR TAU 60-72 RANGING FROM 49 KNOTS (HAFS-A) TO AS HIGH AS 83 KNOTS (HWRF). THE JTWC INTENSITY FORECAST REMAINS HIGHLY CONSISTENT WITH PREVIOUS WARNINGS SHOWING A PEAK INTENSITY OF 60 KNOTS, HEDGED JUST HIGHER THAN THE INTENSITY CONSENSUS (ICNW) PEAK OF 51 KNOTS. FORECAST CONFIDENCE: TRACK 0 - 72 HR: MEDIUM TRACK 72-120 HR: MEDIUM INTENSITY 0 - 72 HR: HIGH INTENSITY 72-120 HR: MEDIUM// NNNN