WDPN32 PGTW 300900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 06W (KHANUN) WARNING NR 013// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 19.5N 132.7E INITIAL INTENSITY: 70 KTS GEOGRAPHIC REFERENCE: 499 NM SOUTHEAST OF KADENA AB MOVEMENT PAST 6 HOURS: NORTHWARD AT 08 KTS SIGNIFICANT WAVE HEIGHT: 29 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: TYPHOON (TY) 06W HAS CONSOLIDATED QUICKLY OVER THE PAST 12 HOURS WITH A RAGGED EYE EVIDENT IN ANIMATED MULTISPECTRAL SATELLITE IMAGERY, WHICH SUPPORTS THE INITIAL POSITION WITH HIGH CONFIDENCE. THE SYSTEM HAS INCREASED 25 KNOTS OVER THE PAST 24 HOURS FROM 45 KNOTS AT 290600Z TO THE INITIAL INTENSITY OF 70 KNOTS DUE PRIMARILY TO DECREASING NORTHERLY VERTICAL WIND SHEAR, IMPROVING RADIAL OUTFLOW AND A MOISTENING MID- TO UPPER-LEVEL ENVIRONMENT. ANIMATED WATER VAPOR IMAGERY NOW SHOWS STRONG EQUATORWARD OUTFLOW AND ROBUST POLEWARD OUTFLOW, WHICH HAS ALLOWED CORE CONVECTION TO CONSOLIDATE AND SPIRAL BANDING TO IMPROVE AS DEPICTED IN A 300422Z AMSR2 89GHZ MICROWAVE IMAGE. THE AMSR2 WINDSPEED IMAGE SHOWS A NARROW BAND OF 60-68 KNOT WINDS OVER THE EASTERN SEMICIRCLE WITH AN OBLONG WIND FIELD ORIENTED FROM THE SSW TO THE NNE. THIS IMAGE SUPPORTS THE INITIAL INTENSITY ASSESSMENT OF 70 KNOTS AS WELL AS THE ADJUSTED WIND RADII. THE MOST RECENT D-PRINT AND D-MINT ESTIMATES SUPPORT THE INITIAL INTENSITY ASSESSMENT WITH REALISTIC ESTIMATES WHILE DVORAK ESTIMATES RANGE FROM 55 TO 90 KNOTS. INITIAL WIND RADII BASIS: AMSR2 DATA: DETAILED ANALYSIS OF THE ASYMMETRIC WIND FIELD REVEALED IN THE AMSR2 WINDSPEED IMAGE. CURRENT STEERING MECHANISM: DEEP-LAYERED SUBTROPICAL RIDGE (STR) CENTERED SE OF TOKYO WITH RIDGE EXTENDING SOUTHWARD. AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T4.0 - 65 KTS RJTD: T3.5 - 55 KTS RCTP: T4.5 - 77 KTS KNES: T5.0 - 90 KTS CIMSS SATCON: 74 KTS AT 300436Z CIMSS ADT: 57 KTS AT 300530Z D-PRINT: 72 KTS AT 300700Z D-MINT: 69 KTS AT 300422Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE VWS: 0-5 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: THE JTWC FORECAST REMAINS HIGHLY CONSISTENT WITH THE PREVIOUS JTWC FORECASTS WITH SOME MINOR SHIFTS IN TRACK NEAR OKINAWA ASSOCIATED WITH POSITIONAL UNCERTAINTY AND SHORT-TERM TRACK CHANGES. OVER THE PAST 3 DAYS, JTWC FORECASTS HAVE REMAINED WITHIN A 50NM ENVELOPE JUST TO THE SOUTH OF OKINAWA. TY 06W WILL TURN GRADUALLY WEST-NORTHWESTWARD AFTER TAU 24 UNDER THE STEERING INFLUENCE OF THE STR POSITIONED TO THE NORTH AND NORTHEAST WITH LANDFALL EXPECTED OVER THE EASTERN CHINA COAST NEAR TAU 84. THE SYSTEM IS EXPECTED TO WEAKEN RAPIDLY AS IT TRACKS INLAND OVER EASTERN CHINA. MODEL DISCUSSION: THE 300000Z ECMWF (EPS) AND GFS (GEFS) ENSEMBLES INDICATE A BIFURCATION IN PROBABILISTIC GUIDANCE WITH TWO DISTINCT CLUSTERS. THE FIRST CLUSTER SUPPORTS A WNW TRACK INTO CENTRAL CHINA AND DISSIPATION SCENARIO. THE SECOND CLUSTER REVEALS A POLEWARD TRACK OVER THE EAST CHINA SEA TOWARD WESTERN JAPAN AND THE KOREAN PENSINSULA (NOTE: THIS COVERS THE NEXT 5 DAYS ONLY). DETERMINISTIC GUIDANCE REMAINS IN TIGHT AGREEMENT THROUGH TAU 48 WITH A CROSS-TRACK SPREAD NEAR OKINAWA RANGING FROM 45NM AT TAU 36 TO 70 NM AT TAU 48. ALTHOUGH THE JTWC FORECAST DOES NOT INDICATE RAPID INTENSIFICATION, RAPID INTENSIFICATION (RI) IS POSSIBLE OVER THE NEXT TWO DAYS WITH RI GUIDANCE TRIGGERED AND THE 300000Z COAMPS-TC ENSEMBLE INDICATING A 10 TO 20 PERCENT PROBABILITY OF RI. AFTER TAU 48, DETERMINISTIC GUIDANCE DIVERGES WITH GFS, AEMN AND JGSM SLOWING AND TURNING POLEWARD WHILE ECMWF, EEMN, NAVGEM AND UKMO TRACK THE SYSTEM WNW INTO EASTERN CHINA. THE JTWC FORECAST PHILOSOPHY CONTINUES TO FAVOR THE WNW MODEL GROUPING AND TRACK OVERLAND. THE MAJOR PROBLEM WITH GFS IS THAT THE MODEL IS TRACKING THE SYSTEM INTO THE STR TO THE NORTH WITH NO DYNAMIC SHORTWAVE TROUGH EVIDENT IN THE ZONAL MIDLATITUDE FLOW. IN FACT, THE MIDLATITUDE WESTERLIES AND BAROCLINIC ZONE ARE DISPLACED WELL TO THE NORTH OF 40N WITH A BROAD MIDLATITUDE RIDGE OVER NORTHEAST CHINA AND MANCHURIA. GFS RAPIDLY BREAKS THIS STR DOWN AND ENVELOPS THE SYSTEM WITHIN A SUBTROPICAL TROUGH WEST OF A NORTH-SOUTH ORIENTED STR, WHICH EVENTUALLY DRIVES THE SYSTEM POLEWARD. THIS SCENARIO IS POSSIBLE BUT IS CURRENTLY ASSESSED AS A LOW PROBABILITY. FORECAST CONFIDENCE: TRACK 0 - 72 HR: MEDIUM TRACK 72-120 HR: LOW INTENSITY 0 - 72 HR: MEDIUM INTENSITY 72-120 HR: LOW// NNNN