WDPN31 PGTW 040300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 12W (HINNAMNOR) WARNING NR 028// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 26.1N 124.5E INITIAL INTENSITY: 105 KTS GEOGRAPHIC REFERENCE: 179 NM WEST OF KADENA AB MOVEMENT PAST 6 HOURS: NORTHWARD AT 10 KTS SIGNIFICANT WAVE HEIGHT: 45 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS THAT TY 12W HAS RAPIDLY CONSOLIDATED AND INTENSIFIED OVER THE PAST SIX HOURS, WITH A SYMMETRIC 45-NM CORE OF DEEP CONVECTION AND A 10-NM EYE. ANIMATED RADAR DATA AND A 032242Z GMI 89GHZ MICROWAVE IMAGE REVEALED THE INNER CORE, COCOONED WITHIN A MUCH LARGER, APPROXIMATELY 120NM DIAMETER SECONDARY EYEWALL. SOMEWHAT SURPRISINGLY, WITH SUCH A STRONG SECONDARY EYEWALL, THE INNER CORE AND EYE HAVE BEEN ABLE TO SUSTAIN AND GROW STRONGER AND SHOW NO SIGN OF IMMINENT EROSION DUE TO BEING CUTOFF FROM ANY SIGNIFICANT INFLOW. ITS ALMOST AS IF THERE IS A VERY SMALL ANNULAR TYPHOON NESTED INSIDE A LARGER TROPICAL CYCLONE LIKE A MATRYOSHKA DOLL. WHILE THE INNER CORE IS VERY SMALL, THE GALE-FORCE WIND FIELD CONTINUES TO EXPAND AND NOW ENCOMPASSING THE MAJORITY OF THE EAST CHINA SEA. THE SYSTEM IS WOBBLING GENERALLY NORTHWARD WITH THE TRACK MADE GOOD JUST A HAIR WEST OF DUE NORTH OVER THE PAST SIX HOURS AND HAS REACHED CPA TO OKINAWA. THE INITIAL POSITION IS ASSESSED WITH HIGH CONFIDENCE BASED ON THE MSI, RADAR AND MICROWAVE EYES. THE INITIAL INTENSITY IS ASSESSED AT 105 KNOTS WITH HIGH CONFIDENCE, HEDGED ABOVE THE BULK OF THE AGENCY FIXES AS A NOD TO THE SATCON, AND EXPERIMENTAL CIMSS DEEP MULTINET (110KTS) AND OPEN-AIIR (107KTS) AND THE RAPID CLEARING OF A NEARLY PINHOLE EYE. INITIAL WIND RADII BASIS: PERSISTENCE CURRENT STEERING MECHANISM: WESTERN PERIPHERY OF A DEEP-LAYER SUBTROPICAL RIDGE (STR) TO THE EAST AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T5.0 - 90 KTS RJTD: T5.0 - 90 KTS KNES: T6.0 - 115 KTS CIMSS SATCON: 106 KTS AT 032217Z CIMSS ADT: 97 KTS AT 040010Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE VWS: 5-10 KTS SST: 29-30 CELSIUS OUTFLOW: STRONG POLEWARD AND EQUATORWARD OTHER FACTORS: CONCENTRIC EYEWALL, DRY AIR ENTRAINMENT OFF TAIWAN ANALYSIS CONFIDENCE: INITIAL POSITION: HIGH 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: HAVING MOVED NORTH INTO THE WARM WATERS OF THE EAST CHINA SEA THIS MORNING, TY 12W HAS CLEARLY GOTTEN ITS ACT TOGETHER AND BEGUN TO RAPIDLY INTENSIFY UNDER FAVORABLE ENVIRONMENTAL CONDITIONS. THE SYSTEM WILL CONTINUE TO TRACK GENERALLY NORTHWARD, WITH SOME CONTINUED DEVIATIONS RIGHT AND LEFT OF DUE NORTH DUE TO WOBBLE, ALONG THE WESTERN SIDE OF THE DEEP STEERING RIDGE TO THE EAST THROUGH THE NEXT 12 HOURS OR SO. THEN AROUND TAU 24, IT WILL MAKE A SHARP TURN TO THE NORTHEAST AS IT ROUNDS THE RIDGE. ONCE FIRMLY ON THE NORTHEAST TRACK, ITS OFF TO THE RACES, WITH TRACK SPEEDS DOUBLING WITHIN 24 HOURS AS THE SYSTEM MOVES ALONG THE TIGHT DEEP-LAYER GRADIENT BETWEEN THE RIDGE TO THE EAST AND AN UNSEASONABLY STRONG UPPER-LEVEL LOW AND TROUGH MOVING IN FROM THE WEST. WHILE THERE REMAINS SOME DRY AIR ENTRAINMENT FLOWING OFF TAIWAN INTO THE SOUTHWESTERN SIDE OF THE STORM, THE ATMOSPHERE DOWN TRACK IS MORE MOIST AND THERE IS PLENTY OF WARM WATER AHEAD. SHEAR IS ALSO EXPECTED TO REMAIN AT OR BELOW 10 TO 15 KNOTS MAX FOR THE NEXT 24 TO 36 HOURS. LASTLY, WHILE OUTFLOW TO THE WEST IS STILL LIMITED, THIS IS MORE THAN OFFSET BY THE VERY STRONG OUTFLOW TO THE EAST AND EQUATORWARD. THE OUTFLOW PATTERN IS SET TO BECOME EVEN BETTER OVER THE NEXT 24 HOURS AS A JET MAXIMUM SKIRTS ACROSS THE BOHAI GULF, AND TY 12W ESTABLISHES A TAP INTO THE DIVERGENT RIGHT FRONT EXIT REGION OF THE JET MAX. IN OTHER WORDS, THE ENVIRONMENT SUPPORTS ADDITIONAL INTENSIFICATION THROUGH TAU 36. HOWEVER, THE CURRENT CONCENTRIC EYEWALL SETUP, AND INCREASING M-PERC EYEWALL REPLACEMENT CYCLE (ERC) PROBABILITIES SUGGEST THE START OF AN ERC IN THE NEAR FUTURE. SO THE PEAK WILL PROBABLY OCCUR WITHIN THE NEXT 12 HOURS AT 115 KNOTS, POTENTIALLY SLIGHTLY HIGHER, BUT THEN BE ARRESTED BY THE ERC. DUE TO THE SPEED OF ADVANCE, AND MOVEMENT OVER STEADILY COOLER WATERS, IT IS UNLIKELY THAT TY 12W WILL REINTENSIFY MUCH AFTER THE COMPLETION OF THE ERC. AFTER TAU 36 THE PARTY IS OVER, AS SHEAR DRAMATICALLY AND SHARPLY INCREASES AND OVERCOMES THE VERY IMPRESSIVE POLEWARD OUTFLOW AND THE SYSTEM BEGINS TO WEAKEN WHILE BEGINNING EXTRA-TROPICAL TRANSITION (ETT). WHILE WEAKENING AS A TROPICAL CYCLONE, THE STRONG MID-LATITUDE DYNAMICS ASSOCIATED WITH THE DEEP TROUGH TO THE NORTHWEST WILL MANAGE TO KEEP THE INTENSITY UP AS THE SYSTEM MAKES LANDFALL ALONG THE COAST OF SOUTH KOREA AROUND TAU 48. THE SYSTEM WILL THEN MOVE RAPIDLY INTO THE SEA OF JAPAN AND TRANSITION TO A WARM SECLUSION TYPE EXTRA-TROPICAL LOW AS EARLY AS TAU 60. MODEL DISCUSSION: TRACK GUIDANCE REMAINS IN VERY GOOD AGREEMENT AND VERY CONSISTENT WITH THE PREVIOUS RUNS. SPREAD IS MINIMAL, LESS THAN 100NM THROUGH THE FORECAST PERIOD, THOUGH ALONG-TRACK SPREAD INCREASES SIGNIFICANTLY AFTER TAU 48 AS THE SYSTEM GOES EXTRA-TROPICAL. THE JTWC FORECAST ALSO REMAINS CONSISTENT WITH THE PREVIOUS FORECAST AND THE MULTI-MODEL CONSENSUS WITH HIGH CONFIDENCE. INTENSITY GUIDANCE IS IN POOR AGREEMENT, WITH SEVERAL OF THE RAPID INTENSIFICATION (RI) AIDS TRIGGERING WITH THIS RUN, UP TO RI45 WHICH WOULD PEAK AT 150 KNOTS AT TAU 36. MEANWHILE THE REMAINDER OF THE INTENSITY PACKAGE IS NOT IMPRESSED BY TY 12W AND SHOW STAGNATION OR IMMEDIATE AND CONTINUED WEAKENING, WITH THE COAMPS-TC NOW DOING A FLIP-FLOP AND NOW COMMITTED TO IMMEDIATE WEAKENING TO 75 KNOTS BY TAU 24, AN UNLIKELY SOLUTION. THE JTWC FORECAST TRACKS THE RI GUIDANCE THROUGH TAU 12 BUT THEN REJOINS THE HIGHER END OF THE PACK BY TAU 24 THEN REMAINS ON THE HIGH EDGE OF THE GUIDANCE THROUGH THE REMAINDER OF THE FORECAST PERIOD. CONFIDENCE IS MEDIUM TO LOW DUE TO THE UNCERTAINTY IN THE TIMING AND IMPACTS OF THE ERC AND THE SUBSEQUENT ALIGNMENT WITH THE OTHER HIGHLY FAVORABLE FACTORS. FORECAST CONFIDENCE: TRACK 0 - 72 HR: HIGH INTENSITY 0 - 72 HR: MEDIUM// NNNN