WDPN31 PGTW 060900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR SUPER TYPHOON 09W (BAVI) WARNING NR 022// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 14.9N 144.0E INITIAL INTENSITY: 145 KTS GEOGRAPHIC REFERENCE: 89 NM NORTHWEST OF ANDERSEN AFB MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 11 KTS SIGNIFICANT WAVE HEIGHT: 52 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A CLASSIC SUPER TYPHOON (STY) CHARACTERIZED BY A CIRCULAR, 20 NM-WIDE EYE EMBEDDED WITHIN A NEARLY SYMMETRIC CENTRAL DENSE OVERCAST (CDO), FLANKED BY A PROMINENT BANDING FEATURE ON THE NORTHWEST PERIPHERY OF THE CIRCULATION. THE DEEP CLOUD TOPS OF THE CDO REMAIN COLD, WITH WHITE AND CMG SHADES ENCIRCLING THE CENTER ON INFRARED IMAGERY ENHANCED VIA THE BD CURVE, WHILE THE EYE IS WELL-DEFINED AND WARM AT 19 DEGREES CELSIUS. WESTWARD OUTFLOW IS ROBUST, AIDED BY AN UPSTREAM, UPPER-LEVEL TROUGH, BUT LIGHT TO MODERATE EASTERLY VERTICAL WIND SHEAR (VWS) IS INHIBITING VENTILATION ON THE EASTERN SIDE. THE VWS IS FURTHER CAUSING SLIGHT ASYMMETRIES WITHIN THE CDO AS THE CORE CONVECTION ATTEMPTS TO FIGHT OFF THE SHEAR. A LACK OF SUCCESSFUL HIGH-RESOLUTION MICROWAVE PASSES SINCE THE 052050Z SSMIS PASS LIMITS DIRECT OBSERVATION OF THE INNER CORE STRUCTURE. ALTHOUGH THAT EARLIER PASS DEPICTED MULTIPLE PARTIAL RAINBANDS, IT WAS INCONCLUSIVE FOR THE ONSET OF AN EYEWALL REPLACEMENT CYCLE (ERC), LEAVING THE CURRENT STATE OF THE INNER-CORE DYNAMICS UNCERTAIN. THE SYSTEM IS BEGINNING TO TRACK AWAY FROM THE DEEPEST POOL OF VERY HIGH OCEAN HEAT CONTENT (OHC) OF 150 KJ PER SQUARE CM. DESPITE THIS, THE SEA SURFACE TEMPERATURE (SST) IS VERY WARM AT 30-31 DEGREES CELSIUS. THESE FACTORS CONSTITUTE FAVORABLE CONDITIONS FOR SUPPORTING THE HIGH-END INTENSITY OF STY BAVI. THE INITIAL POSITION IS ASSESSED WITH HIGH CONFIDENCE BASED ON THE CLEAR, CIRCULAR EYE ON MSI. THE INITIAL INTENSITY HAS BEEN LOWERED TO 145 KTS WITH MEDIUM CONFIDENCE BASED ON A BLEND OF THE SUBJECTIVE DVORAK FIXES RANGING FROM T7.0 TO T7.5. INITIAL WIND RADII BASIS: PERSISTENCE CURRENT STEERING MECHANISM: EASTERN EXTENSION OF A DEEP-LAYER SUBTROPICAL RIDGE (STR) CENTERED NEAR OKINAWA AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T7.0 - 140 KTS RJTD: T7.5 - 155 KTS RCTP: T7.5 - 155 KTS KNES: T7.0 - 140 KTS CIMSS SATCON: 135 KTS AT 060600Z CIMSS ADT: 134 KTS AT 060600Z CIMSS AIDT: 134 KTS AT 060600Z CIMSS D-MINT: 134 KTS AT 060414Z CIMSS D-PRINT: 141 KTS AT 060600Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE VWS: 15-20 KTS SST: 30-31 CELSIUS OUTFLOW: STRONG WESTWARD ANALYSIS CONFIDENCE: INITIAL POSITION: HIGH INITIAL INTENSITY: MEDIUM INITIAL WIND RADII: LOW 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: NOW DOWNSTREAM OF THE MARIANA ISLANDS, STY 09W WILL CONTINUE TRACKING AWAY ON A WEST-NORTHWEST TRAJECTORY UNDER THE STEERING INFLUENCE OF THE STR EXTENSION. THE SYSTEM'S FORWARD MOTION WILL REMAIN STEADY AT 11-14 KTS THROUGH TAU 48, AFTER WHICH THE VORTEX WILL REACH THE SOUTHWESTERN PERIPHERY OF THE RIDGE. SUBSEQUENTLY, THE RIDGE WILL BUILD TO THE EAST, INDUCING A POLEWARD TURN TOWARD THE NORTHWEST FOR THE REMAINDER OF THE FORECAST. THE EXACT MAGNITUDE OF THIS POLEWARD TURN WILL DEPEND ON THE STRENGTH OF THE EASTERN RIDGE AND THE WESTERN EXTENSION OF THAT FEATURE. ENVIRONMENTAL CONDITIONS WILL GENERALLY BE FAVORABLE FOR THE FIRST 24 HOURS, CHARACTERIZED BY HIGH OHC AND LOW TO MODERATE VWS. BY TAU 36, AN UPPER-LEVEL RIDGE BUILDING TO THE NORTH WILL GENERATE 20-25 KTS OF EASTERLY VWS, INITIATING A GRADUAL WEAKENING TREND. THE POTENTIAL FOR ERC, THE TIMING AND DURATION OF WHICH CANNOT BE RELIABLY PREDICTED, REDUCES CONFIDENCE IN THE OVERALL INTENSITY FORECAST. MORE SUBSTANTIAL WEAKENING WILL OCCUR IN THE EXTENDED FORECAST AS THE SYSTEM TRAVERSES LOWER SST AND OHC AT TAU 96, FOLLOWED BY PHYSICAL INTERACTION WITH THE MOUNTAINOUS TERRAIN OF TAIWAN BY TAU 120. MODEL DISCUSSION: MODEL GUIDANCE IS IN TIGHT AGREEMENT ON THE WEST-NORTHWEST MOTION OF STY 09W THROUGH TAU 60. BEYOND THIS POINT, THE CROSS-TRACK SPREAD INCREASES TO 160 NM AT TAU 72, 200 NM AT TAU 96, AND 300 NM AT TAU 120. NAVGEM AND THE MAJORITY OF THE AI MODELS HAVE SHIFTED POLEWARD, WHEREAS THE PHYSICS-BASED MODELS REMAINED RELATIVELY STABLE. THIS BIFURCATED BEHAVIOR HAS BEEN A TREND OVER THE PAST FOUR MODEL CYCLES. THE JTWC FORECAST TRACK IS POSITIONED NEAR THE MULTI-MODEL CONSENSUS WITH HIGH CONFIDENCE FOR THE FIRST 72 HOURS BUT IS NUDGED POLEWARD OF THE CONSENSUS AFTER TAU 72 WITH MEDIUM CONFIDENCE. THIS POLEWARD TRACK ADJUSTMENT NOW PLACES OKINAWA WITHIN THE EXPANSIVE GALE-FORCE WIND RADII. COAMPS-TC HOLDS THE INTENSITY AT 145 KTS THROUGH TAU 24. HWRF IS THE HIGH-END OUTLIER BY KEEPING THE INTENSITY AT 145-150 KTS THROUGH TAU 72. CONVERSELY, COAMPS-TC, HAFS-A, AND THE EXPERIMENTAL GOOGLE DEEPMIND MODEL DEPICT A SLOW TO GRADUAL WEAKENING TREND FOR THE FIRST THREE DAYS, FOLLOWED BY A SHARPER RATE OF DECAY THEREAFTER. THE JTWC INTENSITY FORECAST ALIGNS CLOSELY WITH THIS CONSENSUS PHILOSOPHY AND IS SET CLOSEST TO COAMPS-TC THROUGH TAU 72 AND HAFS-A AND DEEPMIND AT TAU 96 AND TAU 120 WITH MEDIUM CONFIDENCE. FORECAST CONFIDENCE: TRACK 00-72 HR: HIGH TRACK 72-120 HR: MEDIUM INTENSITY 00-72 HR: MEDIUM INTENSITY 72-120 HR: MEDIUM// NNNN