WDPN33 PGTW 130900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 24W (KOMPASU) WARNING NR 013// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 19.2N 110.7E INITIAL INTENSITY: 55 KTS GEOGRAPHIC REFERENCE: 291 NM EAST-SOUTHEAST OF HANOI, VIETNAM MOVEMENT PAST 6 HOURS: WESTWARD AT 19 KTS SIGNIFICANT WAVE HEIGHT: 21 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) AND RADAR IMAGERY DEPICT DEEP CONVECTIVE BANDING WRAPPING INTO A DEFINED LOW-LEVEL CIRCULATION CENTER POSITIONED JUST OFF THE EAST COAST OF HAINAN ISLAND. THUS, THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE. THE INITIAL INTENSITY OF 55 KTS IS ASSESSED WITH HIGH CONFIDENCE BASED ON AGENCY DVORAK ESTIMATES. ENVIRONMENTAL ANALYSIS REVEALS A MARGINALLY FAVORABLE ENVIRONMENT WITH STRONG EASTERLY VERTICAL WIND SHEAR OFFSET BY MODERATE POLEWARD AND EQUATORWARD OUTFLOW. INITIAL WIND RADII BASIS: SCATTEROMETER DATA CURRENT STEERING MECHANISM: DEEP-LAYERED SUBTROPICAL RIDGE (STR) ENTRENCHED TO THE NORTH. AGENCY DVORAK AND AUTOMATED FIXES: PGTW: NO CURRENT ESTIMATE RJTD: T3.5 - 55 KTS RCTP: T3.5 - 55 KTS KNES: T3.5 - 55 KTS CIMSS SATCON: 56 KTS AT 130557Z CIMSS ADT: 49 KTS AT 130540Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE VWS: 25-30 KTS SST: 27-28 CELSIUS OUTFLOW: MODERATE POLEWARD AND EQUATORWARD ANALYSIS CONFIDENCE: INITIAL POSITION: HIGH INITIAL INTENSITY: MEDIUM INITIAL WIND RADII: MEDIUM 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TS 24W IS FORECAST TO TRACK QUICKLY WESTWARD UNDER THE DEEP-LAYERED STR ENTRENCHED TO THE NORTH. THE SYSTEM WILL STEADILY WEAKEN AS IT TRACKS OVER HAINAN ISLAND WITH MORE RAPID WEAKENING AFTER TAU 24 WHEN THE SYSTEM MAKES LANDFALL OVER VIETNAM AND TRACKS INLAND. TS 24W WILL DISSIPATE BY TAU 48. MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE IS IN GOOD AGREEMENT THROUGH TAU 24 BUT DIVERGES OVER LAND WHEN THE SYSTEM RAPIDLY WEAKENS. INTENSITY GUIDANCE IS IN GOOD AGREEMENT AND SUPPORTS THE STEADY WEAKENING TREND. FORECAST CONFIDENCE: TRACK 0 - 72 HR: HIGH INTENSITY 0 - 72 HR: MEDIUM// NNNN