WDPN31 PGTW 091500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 02W (MALAKAS) WARNING NR 011// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 8.4N 143.0E INITIAL INTENSITY: 45 KTS GEOGRAPHIC REFERENCE: 298 NM EAST-SOUTHEAST OF YAP MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 10 KTS SIGNIFICANT WAVE HEIGHT: 20 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A CONSOLIDATING SYSTEM WITH FLARING DEEP CENTRAL CONVECTION OBSCURING THE LOW LEVEL CIRCULATION (LLC) THE INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED ON EXTRAPOLATION FROM A DEFINED LLC IN THE 090857Z SSMIS MICROWAVE IMAGE. THE INITIAL INTENSITY OF 45KTS IS BASED ON AN OVERALL ASSESSMENT OF AGENCY AND AUTOMATED DVORAK ESTIMATES AND REFLECTS THE SUSTAINED 6-HR CONVECTIVE SIGNATURE. ANALYSIS INDICATES A FAVORABLE ENVIRONMENT WITH MODERATE POLEWARD OUTFLOW AND WARM SST OFFSETTING THE MODERATE TO STRONG VWS. THE CYCLONE IS TRACKING ALONG THE SOUTHWESTERN PERIPHERY OF THE STR TO THE NORTHEAST. INITIAL WIND RADII BASIS: PERSISTENCE. CURRENT STEERING MECHANISM: DEEP-LAYER SUBTROPICAL RIDGE (STR) TO THE NORTHEAST. AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T3.0 - 45 KTS RJTD: T2.5 - 35 KTS RCTP: T3.5 - 55 KTS CIMSS ADT: 53 KTS AT 091140Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE VWS: 15-20 KTS SST: 28-29 CELSIUS OUTFLOW: MODERATE POLEWARD ANALYSIS CONFIDENCE: INITIAL POSITION: MEDIUM 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 MALAKAS WILL CONTINUE TO TRACK NORTHWESTWARD UNDER THE STEERING INFLUENCE OF THE STR. AFTER TAU 36, THE CYCLONE WILL JOG SLIGHTLY WESTWARD AND DECELERATE AS IT INTERACTS WITH A SECONDARY CYCLONE (TD 03W) APPROACHING FROM THE SOUTHWEST. AFTERWARD, IT WILL ROUND THE STR AXIS THEN RECURVE NORTHEASTWARD TOWARD IWO TO. THE FAVORABLE ENVIRONMENT WILL FUEL A STEADY INTENSIFICATION TO 85KTS BY TAU 48. AFTERWARD, AS THE CYCLONE REACHES THE POLEWARD SIDE OF THE STR AXIS, DECREASED VWS AND INCREASED POLEWARD OUTFLOW DUE TO THE INITIAL EXPOSURE INTO THE PREVAILING WESTERLIES, WILL ENHANCE THE FAVORABLE DYNAMICS AND BRING THE CYCLONE TO ITS PEAK INTENSITY OF 100KTS BY TAU 72. AFTER TAU 72, VWS WILL ONCE AGAIN INCREASE. THIS PLUS THE INFLUX OF COOL DRY AIR WILL BEGIN TO ERODE THE SYSTEM AND BY TAU 120 WILL BE AT 80KTS. MODEL DISCUSSION: NUMERICAL MODELS ARE IN TIGHT AGREEMENT WITH A GRADUAL AND EVEN SPREAD TO 215NM BY TAU 120. HOWEVER, GIVEN SOME UNCERTAINTY WITH THE IMPACT OF BINARY INTERACTION WITH TD 02W, THERE IS ONLY MEDIUM CONFIDENCE IN THE JTWC TRACK FORECAST. FORECAST CONFIDENCE: TRACK 0 - 72 HR: MEDIUM TRACK 72-120 HR: MEDIUM INTENSITY 0 - 72 HR: MEDIUM INTENSITY 72-120 HR: MEDIUM// NNNN