WDPN31 PGTW 220900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 06W (SIX) WARNING NR 006// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 13.9N 142.5E INITIAL INTENSITY: 35 KTS GEOGRAPHIC REFERENCE: 140 NM WEST OF ANDERSEN AFB, GUAM MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 11 KTS SIGNIFICANT WAVE HEIGHT: 13 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS THE CENTRAL CONVECTION HAS EXPANDED, DEEPENED, AND TOTALLY OBSCURED THE LOW LEVEL CIRCULATION (LLC). RAIN BANDS, MOSTLY EMANATING FROM THE EAST, REMAIN WEAK AND FRAGMENTED, HOWEVER. THE INITIAL POSITION IS BASED ON A RAGGED LLC FEATURE IN THE 220615Z GPM MICROWAVE IMAGE. THE INITIAL INTENSITY IS BASED ON THE HIGH END OF AGENCY AND ADT DVORAK ESTIMATES AND REFLECTS THE IMPROVED 6-HR MSI SIGNATURE OF THE SYSTEM. THE ENVIRONMENT IS MARGINALLY FAVORABLE WITH WARM SSTS AND LOW VWS TEMPERED BY A WEAK POLEWARD OUTFLOW. THE CYCLONE IS TRACKING ALONG THE SOUTHWEST PERIPHERY OF THE LOW- TO MID-LEVEL REFLECTION OF THE STR TO THE NORTHEAST. INITIAL WIND RADII BASIS: PERSISTENCE CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE TO THE NORTHEAST AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T2.0 - 30 KTS RJTD: T2.0 - 30 KTS KNES: T2.0 - 30 KTS CIMSS ADT: 37 KTS AT 220540Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE VWS: 5-10 KTS SST: 30-31 CELSIUS OUTFLOW: WEAK POLEWARD ANALYSIS CONFIDENCE: INITIAL POSITION: MEDIUM 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: TS 06W WILL CONTINUE ON ITS CURRENT TRACK THEN TURN MORE NORTHWARD AFTER TAU 48 AND CREST THE STR AXIS BY TAU 72. AFTERWARD, IT WILL ACCELERATE NORTH-NORTHEASTWARD, THEN AFTER TAU 96, NORTHEASTWARD ON THE POLEWARD SIDE OF THE STR. THE MARGINALLY FAVORABLE ENVIRONMENT WILL FUEL A STEADY INTENSIFICATION TO A PEAK OF 65KTS BY TAU 72. AFTERWARD, INCREASING VWS AND COOLING SSTS WILL SLOWLY ERODE THE CYCLONE. CONCURRENTLY BY TAU 96, IT WILL BEGIN EXTRA-TROPICAL TRANSITION (ETT) AS IT ENTERS THE COLD BAROCLINIC ZONE AND MERGES WITH THE BAIYU FRONTAL BOUNDARY SOUTHEAST OF JAPAN. BY TAU 120, TS 06W WILL COMPLETE ETT AND EMBED INTO THE GRADIENT FLOW AS A STORM-FORCE COLD CORE LOW WITH AN EXPANSIVE WIND FIELD. MODEL DISCUSSION: NUMERICAL MODELS ARE IN OVERALL GOOD AGREEMENT WITH GRADUAL SPREADING TO 160NM AT TAU 72 AND 200NM AT TAU 120. JGSM IS THE SOLE LEFT-OF-TRACK OUTLIER. THIS LENDS MEDIUM CONFIDENCE TO THE JTWC TRACK FORECAST THAT IS LAID JUST TO THE RIGHT OF AND SLIGHTLY FASTER THAN THE MODEL CONSENSUS AFTER TAU 72 TO OFFSET JGSM. FORECAST CONFIDENCE: TRACK 0 - 72 HR: MEDIUM TRACK 72-120 HR: MEDIUM INTENSITY 0 - 72 HR: HIGH INTENSITY 72-120 HR: MEDIUM// NNNN