WDPN32 PGTW 020900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 06W (KHANUN) WARNING NR 025// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 26.1N 126.2E INITIAL INTENSITY: 100 KTS GEOGRAPHIC REFERENCE: 89 NM WEST-SOUTHWEST OF KADENA AB MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 08 KTS SIGNIFICANT WAVE HEIGHT: 36 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A WELL DEFINED TYPHOON STRENGTH CIRCULATION WITH A ROUGHLY 20NM EYE AND EXTENSIVE DEEP CONVECTIVE BANDING FEATURES IN ALL QUADRANTS. A RECENT 020454Z AMSR2 89GHZ MICROWAVE IMAGE REVEALS A TIGHT INNER EYEWALL WITH A PRONOUNCED, ROUGHLY 90NM MOAT. BEYOND WHICH IS THE SECONDARY EYEWALL. RECENT MICROWAVE IMAGERY AND INCREASING MICROWAVE PROBABILITY OF EYEWALL REPLACEMENT CYCLE (M-PERC) VALUES, INDICATE AN EYEWALL REPLACEMENT CYCLE (ERC) IS LIKELY UNDERWAY. 020153Z ASCAT-B SCATTEROMETERY AND NEWER 020453Z AMSR2 SCALAR WIND PRODUCTS BOTH INDICATE A LARGE WIND FIELD WITH A MAJORITY OF THE HIGHEST WINDS IN THE NORTHERN SEMICIRCLE. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON MSI AND AMSR2 IMAGERY. THE INITIAL INTENSITY OF 100 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON A MAJORITY OF INTENSITY GUIDANCE, SUCH AS CIMSS ADT, AIDT, D-MINT, D-PRINT AND AGENCY DVORAK INTENSITY ESTIMATES FALLING CLOSE TO THE JTWC INITIAL INTENSITY WITH MINIMAL VARIABILITY. INITIAL WIND RADII BASIS: SCATTEROMETER DATA CURRENT STEERING MECHANISM: A DEEP-LAYER SUBTROPICAL RIDGE (STR) CENTERED OVER THE YELLOW SEA TO THE NORTH AND A NEAR-EQUATORIAL (NER) CENTERED TO THE SOUTHEAST. AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T5.5 - 102 KTS RJTD: T5.5 - 102 KTS RCTP: T5.5 - 102 KTS KNES: T5.5 - 102 KTS CIMSS SATCON: 118 KTS AT 020433Z CIMSS ADT: 102 KTS AT 020530Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE VWS: 0-5 KTS SST: 29-30 CELSIUS OUTFLOW: MODERATE EASTWARD 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: TY 06W (KHANUN) IS FORECAST TO CONTINUE WEST-NORTHWESTWARD OVER THE NEXT 36 HOURS. DURING THAT TIME, AN ONGOING ERC WILL INDUCE LIMITED SHORT TERM WEAKENING THAT WILL EVENTUALLY BE EXACERBATED BY UPWELLING OF COOLER WATERS BENEATH 06W. THIS UPWELLING TAKES PLACE NEAR TAU 36, THE STR OVER THE YELLOW SEA BEGINS TO SHIFT WESTWARD AND BLOCKS ANY FURTHER MOVEMENT TOWARDS MAINLAND CHINA. AS TRACK SPEEDS GRIND TO A HALT, UPWELLING BEGINS TO QUICKLY WEAKEN THE SYSTEM. BY TAU 48, THE SYSTEM IS FORECAST TO MOVE GENERALLY EAST-NORTHEASTWARD EVENTUALLY PICKING UP SPEED WHILE CONTINUING TO WEAKEN. BEYOND TAU 72 HAS SEEN SOME OF THE GREATEST RUN TO RUN VARIABILITY, THANKS IN PART TO RIDGING, OR LACK THEREOF, TO THE NORTHEAST OF THE SYSTEM AS IT ONCE AGAIN PASSES KADENA AB. FOR THE TIME BEING, THE PREPONDERANCE OF MODEL GUIDANCE, BOTH DETERMINISTIC AND ENSEMBLE, LENDS SLIGHTLY HIGHER CREDENCE TO A PERSISTENT EAST-NORTHEASTERLY COURSE FOLLOWING TAU 72. MODEL DISCUSSION: WITH THE EXCEPTION OF NVGM, NUMERICAL MODELS ARE IN GOOD AGREEMENT THROUGH TAU 36 WITH A BULK OF THE GUIDANCE GENERALLY FOLLOWING THE JTWC TRACK FORECAST. FOLLOWING TAU 36, ALL MEMBERS EXECUTE A SHARP EAST-NORTHEASTWARD TURN, THOUGH SPREADING, BOTH ALONG TRACK AND CROSS TRACK DOES WORSEN WITH TIME. FOR THESE REASONS THE JTWC TRACK FORECAST IS PLACED INITIALLY WITH MEDIUM CONFIDENCE AND WITH LOW CONFIDENCE THEREAFTER. RELIABLE MODEL INTENSITY GUIDANCE IS IN FAIR AGREEMENT WITH ALL MEMBERS INDICATING SLIGHT WEAKENING THROUGH TAU 24 AND MORE DRAMATIC WEAKENING THEREAFTER, WITH MINIMAL DEVIATION FROM THE MULTI-MODEL CONSENSUS. FOR THIS REASON THE JTWC INTENSITY FORECAST IS PLACED WITH OVERALL MEDIUM CONFIDENCE. FORECAST CONFIDENCE: TRACK 0 - 72 HR: MEDIUM TRACK 72-120 HR: LOW INTENSITY 0 - 72 HR: MEDIUM INTENSITY 72-120 HR: MEDIUM// NNNN