WDPN31 PGTW 260900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 06W (CHAMPI) WARNING NR 022// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 26.0N 140.0E INITIAL INTENSITY: 60 KTS GEOGRAPHIC REFERENCE: 101 NM NORTHWEST OF IWO TO, JAPAN MOVEMENT PAST 6 HOURS: NORTH-NORTHEASTWARD AT 12 KTS SIGNIFICANT WAVE HEIGHT: 22 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS THE SYSTEM HAS BEGUN TO DETERIORATE AS CENTRAL CONVECTION, ESPECIALLY ALONG THE WESTERN HALF HAS ERODED, PARTIALLY EXPOSING THE LOW LEVEL CIRCULATION (LLC) THAT REMAINS INTACT AND FULLY WRAPPED. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON MSI LOW CLOUD TRACING INTO THE PARTIALLY EXPOSED LLC AND LINED UP WITH A DEFINED MICROWAVE LLC FEATURE IN THE 260358Z AMSR2 PASS. THE INITIAL INTENSITY OF 60 KTS IS ASSESSED WITH HIGH CONFIDENCE BASED ON AN OVERALL ASSESSMENT OF AGENCY AND AUTOMATED DVORAK FIXES AND REFLECTS THE 6-HOUR DETERIORATION. INITIAL WIND RADII BASIS: PERSISTENCE. PROPORTIONALLY REDUCED FROM PREVIOUS WIND RADII. CURRENT STEERING MECHANISM: WESTERN PERIPHERY OF THE STR TO THE EAST-SOUTHEAST. AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T4.0 - 65 KTS RJTD: T4.0 - 65 KTS RCTP: T4.0 - 65 KTS KNES: T3.5 - 55 KTS CIMSS ADT: 53 KTS AT 260510Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: UNFAVORABLE VWS: 15-20 KTS SST: 27-28 CELSIUS OUTFLOW: STRONG POLEWARD ANALYSIS CONFIDENCE: INITIAL POSITION: HIGH INITIAL INTENSITY: HIGH 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 CHAMPI HAS CRESTED THE STR AXIS AND WILL ACCELERATE NORTH-NORTHEASTWARD THEN NORTHEASTWARD ON THE POLEWARD SIDE OF THE STR AND BY TAU 48 WILL 495NM EAST OF MISAWA, JAPAN. THE SYSTEM WILL GRADUALLY WEAKEN AS THE UNFAVORABLE ENVIRONMENT WILL ONLY GET WORSE WITH VWS FURTHER INCREASING TO ABOVE 25KTS AND SSTS COOLING TO BELOW 27C. CONCURENTLY, BY TAU 24, TS 06W WILL BEGIN TO INTERACT WITH THE BAIU BOUNDARY START EXTRA-TROPICAL TRANSITION AND BY TAU 36, WILL TRANSFORM INTO A GALE-FORCE COLD CORE LOW WITH AN EXPANSIVE WIND FIELD AS IT GETS EMBEDDED IN THE BAROCLINIC ZONE. MODEL DISCUSSION: NUMERIC MODELS REMAIN TIGHT AND GRADUALLY AND EVENLY SPREAD TO A MERE 110NM AT TAU 120, LENDING HIGH CONFIDENCE IN THE JTWC TRACK FORECAST. THE JTWC INTENSITY FORECAST IS IN GOOD AGREEMENT WITH MODEL SOLUTIONS WHICH SHOW A STEADY WEAKENING TREND. HWRF REMAINS THE ONE EXCEPTION WHICH INDICATES A BRIEF INTENSIFICATION PERIOD THROUGH TAU 12. FORECAST CONFIDENCE: TRACK 0 - 48 HR: HIGH INTENSITY 0 - 72 HR: MEDIUM// NNNN