WDPN31 PGTW 062100 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 12W (DOLPHIN) WARNING NR 044// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 26.9N 130.4E INITIAL INTENSITY: 80 KTS GEOGRAPHIC REFERENCE: 141 NM EAST OF KADENA AB MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 10 KTS SIGNIFICANT WAVE HEIGHT: 40 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS DISCONTINUOUS DEEP CONVECTIVE BANDING SURROUNDING A COMPACT INNER CORE WITH A SMALL 10 NM RAGGED EYE. THE DEEP CONVECTION SURROUNDING THE INNER CORE THAT MAKES UP THE EYEWALL HAD BEEN ERODING ON THE WESTERN SIDE EARLIER BUT NOW APPEARS TO BE RECONSTITUTING WITHIN THE PAST FEW HOURS. A 061725Z AMSR-2 37 GHZ MICROWAVE IMAGE HIGHLIGHTS THE DISCONTINUOUS STRUCTURE OF THE CONVECTIVE BANDING AND THE WEAKNESS OF CONVECTION IN THE WESTERN SIDE OF THE CORE CONVECTION. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE RAGGED EYE IN IR IMAGERY AND EXTRAPOLATION FROM THE MICROWAVE EYE IN THE AMSR-2 IMAGE. A 051300Z ASCAT-C WIND SPEED PRODUCT REVEALED THE NEARLY 500 NM DIAMETER EXTENT OF GALE FORCE WINDS SURROUNDING THE SYSTEM. NOTABLY, THE ASCAT-C IMAGE SHOWS THAT THE WIND FIELD IN THE SOUTHERN SEMICIRCLE HAS BECOME MORE HOMOGENEOUS AND LESS INTENSE THAN WHAT HAS BEEN OBSERVED OVER THE PAST FEW DAYS. THE INITIAL INTENSITY OF 80 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON UNANIMOUS T4.5 DVORAK CURRENT INTENSITIES FROM THE FIXING AGENCIES, HEDGED SLIGHTLY HIGHER GIVEN THE LITTLE CHANGE IN OVERALL SATELLITE PRESENTATION. THE ENVIRONMENT IS CHARACTERIZED AS FAVORABLE, WITH WARM SEA SURFACE TEMPERATURES, LOW VERTICAL WIND SHEAR (VWS), AND EXCELLENT RADIAL OUTFLOW. INITIAL WIND RADII BASIS: PERSISTENCE CURRENT STEERING MECHANISM: SOUTHWESTERN FLANK OF A SUBTROPICAL RIDGE CENTERED OVER HONSHU AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T4.5 - 77 KTS RJTD: T4.5 - 77 KTS RCTP: T4.5 - 77 KTS KNES: T4.5 - 77 KTS CIMSS SATCON: 73 KTS AT 061800Z CIMSS ADT: 61 KTS AT 061800Z CIMSS AIDT: 72 KTS AT 061800Z CIMSS D-MINT: 75 KTS AT 061749Z CIMSS D-PRINT: 74 KTS AT 061730Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE VWS: 5-10 KTS SST: 29-30 CELSIUS OUTFLOW: STRONG RADIAL 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: TYPHOON (TY) 12W (DOLPHIN) HAS CONTINUED ON A WOBBLING WEST-NORTHWESTWARD TRACK OVER THE PAST 6 HOURS UNDER THE STEERING INFLUENCE OF THE STR OVER HONSHU. THE SYSTEM IS FORECAST TO CONTINUE NEARLY DUE WESTWARD THROUGH TAU 60 AS THE STEERING RIDGE MIGRATES EAST AND A WEAKER RIDGE EXTENSION BUILDS IN FROM THE WEST. THE TRACK SPEED IS EXPECTED TO SLOW SLIGHTLY BETWEEN TAU 36-60 AS THE STEERING GRADIENT WEAKENS BETWEEN THE TWO RIDGE FEATURES. AFTER TAU 60, THE STEERING ENVIRONMENT GETS A BIT MORE COMPLICATED WITH THE PASSAGE OF A MIDLATITUDE TROUGH TO THE NORTH, INTRODUCING SOME UNCERTAINTY IN THE RECURVING TRACK. THE CPA TO KADENA AB AROUND 080900Z IS 42 NM, HOWEVER, THE EXPANSIVE WIND FIELD HAS ALREADY REACHED OKINAWA, WITH 40+ KT GUSTS OBSERVED AT RODN SINCE 1600Z. TY 12W IS EXPECTED TO MAKE LANDFALL IN EASTERN CHINA AROUND TAU 72 AS IT BEGINS TO RECURVE NORTHWESTWARD. THE INTENSITY IS FORECAST TO REMAIN STEADY AROUND 80 KTS UNTIL TAU 48, AFTER WHICH A STEADY WEAKENING TREND WILL BE INITIATED BY LOWER OCEAN HEAT CONTENT AND PROXIMITY TO MAINLAND CHINA. RAPID DISSIPATION IS EXPECTED AS THE SYSTEM RECURVES INLAND OVER EASTERN CHINA. MODEL DISCUSSION: MODEL TRACK GUIDANCE IS IN GOOD AGREEMENT ABOUT THE WESTWARD TRAJECTORY THROUGH TAU 60, THEN SPREADS …