WDPN31 PGTW 020300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 12W (HINNAMNOR) WARNING NR 020// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 21.5N 125.4E INITIAL INTENSITY: 95 KTS GEOGRAPHIC REFERENCE: 328 NM SOUTH-SOUTHWEST OF KADENA AB MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 01 KTS SIGNIFICANT WAVE HEIGHT: 45 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS AN ERODING SYSTEM WITH DEEP CONVECTION OVER THE SOUTHERN SEMICIRCLE AND EVIDENCE OF UPPER LEVEL CONVERGE CREATING PRESSURE OVER THE NORTHERN SEMI-CIRCLE. THE CENTRAL CONVECTION CONTINUES TO SHOW SIGNS OF DECAY DUE TO THE UPWELLING CREATED BY THE QUASI-STATIONARY POSTURE OF TY 12W OVER THE PAST 12 HOURS. IN ADDITION, THE SYSTEM HAS AN EYE THAT HAS BECOME FULLY EMBEDDED UNDER THE CONVECTIVE PLUME OVER THE CENTER OF THE LOW LEVEL CIRCULATION CENTER (LLCC). A 012244Z SSMIS COMPOSITE 37 PASS SHOWS THE CONVECTIVE BANDS ARE IN UNIFORM SHAPE AS THEY CIRCLE THE LLCC WITH THE HEAVIEST CONVECTIVE ACTIVITY IN THE SOUTHEASTERN SEMICIRCLE DUE THE STRONG EQUATORWARD OUTFLOW ALOFT AND THE PRESENCE OF THE WARMEST SEA SURFACE TEMPERATURES NEAR THE SYSTEM. INITIAL WIND RADII BASIS: PERSISTENCE CURRENT STEERING MECHANISM: QUASI-STATIONARY DUE TO BEING NESTED BETWEEN THE AFOREMENTIONED RIDGE TO THE NORTHWEST, THE SUBTROPICAL RIDGE TO THE EAST-NORTHEAST, AND THE NEAR EQUATORIAL RIDGE TO THE SOUTH. AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T5.5 - 102 KTS RJTD: T4.5 - 77 KTS RCTP: T5.0 - 90 KTS KNES: T4.5 - 77 KTS CIMSS SATCON: 78 KTS AT 012245Z CIMSS ADT: 97 KTS AT 012040Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL VWS: 15-20 KTS SST: 28-29 CELSIUS OUTFLOW: STRONG EQUATORWARD OTHER FACTORS: UPWELLING COOLER WATER 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 HINNAMNOR WILL REMAIN SOMEWHAT QUASI-STATIONARY OVER THE NEXT 24 HOURS. AS A RESULT, THE SEA SURFACE TEMPERATURE WILL CONTINUE TO COOL DUE TO IMMENSE UPWELLING AND DECREASE THE OVERALL INTENSITY OF THE SYSTEM TO 90 KTS BY TAU 12 AND WILL REMAIN THIS INTENSITY THROUGH TAU 36. AS TAU 36 APPROACHES, TY 12W WILL BE PICKING UP TRACK SPEED AND TRANSITING NORTHWARD DUE TO THE WEAKENING OF THE SUBTROPICAL RIDGE. AT THE SAME TIME, TY 12W WILL SLOWLY INCREASE IN INTENSITY TO 95 KTS DUE TO THE ENVIRONMENT BECOMING FAVORABLE CHARACTERIZED BY GOOD OUTFLOW ALOFT AND VERY WARM (29-30C) SSTS. BY TAU 72, TY 12W WILL ROUND THE RIDGE AXIS AND MAKE THE A NORTHEASTWARD TURN REACHING ITS MAX INTENSITY OF 115 KTS. SOME ENSEMBLE TRACKERS HAVE TY 12W ON A MORE WESTERLY TRACK WHICH COULD BE A LIMITING FACTOR OF THIS MAX INTENSITY DUE TO COOLER WATERS OFF THE EAST COAST OF CHINA. BY TAU 96, TY 12W WILL BEGIN ITS EXTRA-TROPICAL TRANSITION, AS WELL AS SHOW SIGNS DETERIORATION DUE TO LAND INTERACTION AND COOLER SSTS AS IT APPROACHES THE SOUTHERN COAST OF KOREA, DECREASING IN INTENSITY TO 95 KTS. BY TAU 120, TY 12W WILL BECOME FULLY EXTRA-TROPICAL OVER THE SEA OF JAPAN WITH AN OVERALL INTENSITY OF 65 KTS. MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE REMAINS IN GOOD AGREEMENT IN THE FIRST 72 HOURS, HOWEVER, THE ENVELOPE WILL WIDEN AFTER TAU 72 WITH A 150NM SPREAD AT TAU 96. THIS SPREAD GRADUALLY INCREASES TO 270NM BY TAU 120 WHICH IS MUCH WIDER THAN THE PREVIOUS MODEL RUN. IN ADDITION, UNCERTAINTY REMAINS AMONG THE MODEL MEMBERS WITH TRACK SPEED AFTER TAU 72. THIS, IN ADDITION TO THE WIDER SPREAD, LENDS LOW CONFIDENCE AFTER TAU 72. THERE IS MEDIUM CONFIDENCE IN THE JTWC INTENSITY FORECAST THROUGH TAU 72 AS THE LARGE SPREAD IN INTENSITY GUIDANCE REMAINS AS IT DID ON THE PREVIOUS MODEL RUN. AFTER TAU 72, THE CONFIDENCE REMAINS LOW DUE TO THE TIMING OF EXTRA-TROPICAL TRANSITION, THE INFLUENCE OF THE COOLER SSTS AND LAND INTERACTION AS IT PASSES SOUTHEAST OF THE KOREAN PENINSULA. FORECAST CONFIDENCE: TRACK 0 - 72 HR: MEDIUM TRACK 72-120 HR: LOW INTENSITY 0 - 72 HR: MEDIUM INTENSITY 72-120 HR: LOW// NNNN