WDPN32 PGTW 102100 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 15W (BOLAVEN) WARNING NR 016// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 16.0N 144.5E INITIAL INTENSITY: 100 KTS GEOGRAPHIC REFERENCE: 140 NM NORTH OF ANDERSEN AFB MOVEMENT PAST 6 HOURS: NORTH-NORTHWESTWARD AT 09 KTS SIGNIFICANT WAVE HEIGHT: 35 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: TYPHOON (TY) 15W (BOLAVEN) HAS FINALLY COMMENCED THE LONG-AWAITED RAPID INTENSIFICATION (RI) PHASE, WITH WINDS INCREASING FROM 80 KNOTS TO AT LEAST 100 KNOTS IN JUST THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A 12NM SYMMETRICAL EYE, WITH COLD CLOUD TOPS BELOW -80C SURROUNDING THE EYE FEATURE. A 101545Z AMSR2 89GHZ MICROWAVE IMAGE REVEALED A PINHOLE EYE WITH A STRONG EYEWALL COMPLETELY SURROUNDING THE EYE FEATURE. THE INITIAL POSITION IS ASSESSED WITH HIGH CONFIDENCE BASED ON THE EYE IN THE EIR AS WELL AS EXTRAPOLATION OF THE MICROWAVE EYE AND RADAR FIX DATA. THE INITIAL INTENSITY OF 100 KNOTS WAS ASSESSED AT 1800Z WITH MEDIUM CONFIDENCE, HOWEVER THE LATEST IMAGERY SUGGESTS THE INTENSITY HAS BLOWN RIGHT THROUGH THAT THRESHOLD ALREADY BY 1900Z. DVORAK CURRENT INTENSITY ESTIMATES ALIGNED AT T5.5 TO T6.0 FROM ALL AGENCIES, HOWEVER THE ADT AND AIDT WERE LAGGING BEHIND AS THEY STRUGGLE TO TRACK THE SMALL EYE FEATURE. CIMSS DPRINT IS A LEADING INDICATOR, AND WAS 106 KNOTS AT 1800Z AND IS UP TO 117 KNOTS AT 1900Z. ADDITIONALLY, ANALYSIS OF RADAR VELOCITY DATA SHOWS WINDS EXCEEDING 100 KNOTS AT 25000 FT. WHILE THESE WINDS CANNOT BE EFFECTIVELY REDUCED TO A SURFACE WIND, THE FACT THAT WINDS OF THIS STRENGTH EXIST AT THIS ALTITUDE POINTS TO THE PHENOMENAL STRENGTH OF THE VORTEX. TY 15W IS NOW TAPPING INTO AN NEAR-OPTIMUM ENVIRONMENT, WITH LOW DEEP-LAYER VERTICAL WIND SHEAR (VWS), WARM SSTS, AND HIGH OHC. OUTFLOW REMAINS RELATIVELY MODEST, CONSISTING MOSTLY OF MESOSCALE RADIAL FLOW AND SOME WESTWARD FLOW. ANIMATED WATER VAPOR IMAGERY SHOWS THE FIRST HINTS OF A POLEWARD OUTFLOW CHANNEL AS WELL. INITIAL WIND RADII BASIS: PERSISTENCE CURRENT STEERING MECHANISM: SOUTHWESTERN PERIPHERY OF A DEEP-LAYER SUBTROPICAL RIDGE (STR) CENTERED TO THE NORTHEAST. AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T5.5 - 102 KTS RJTD: T5.5 - 102 KTS KNES: T6.0 - 115 KTS CIMSS SATCON: 96 KTS AT 101615Z CIMSS ADT: 90 KTS AT 101730Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY FAVORABLE VWS: 0-5 KTS SST: 29-30 CELSIUS OUTFLOW: MODERATE RADIAL OTHER FACTORS: DEVELOPING POLEWARD OUTFLOW CHANNEL 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 BOLAVEN IS FORECAST TO TRACK NORTH-NORTHWEST ALONG THE WESTERN SIDE OF THE DEEP STR TO THE NORTHEAST THROUGH THE NEXT 12 HOURS OR SO. TRACK SPEEDS WILL SLOW DOWN A BIT AS THE SYSTEM APPROACHES THE RIDGE AXIS, WITH THE SYSTEM ROUNDING THE AXIS AND TURNING NORTH-NORTHEASTWARD AFTER TAU 24. AFTER TAU 36, THE SYSTEM WILL CONTINUE TO ROUND THE RIDGE AND ACCELERATE NORTHEASTWARD ALONG THE STRONG GRADIENT BETWEEN THE STR AND A DEEP TROUGH TO THE NORTHWEST, PASSING WELL SOUTHEAST OF IWO TO AROUND TAU 48, THEN RAPIDLY ACCELERATING INTO THE OPEN WATERS OF THE NORTH PACIFIC. IN TERMS OF INTENSITY, THE SYSTEM HAS ABOUT 36 HOURS UNDER OPTIMUM ENVIRONMENTAL CONDITIONS WHICH WILL BE ENHANCED FURTHER BY THE DEVELOPMENT OF A STRONG POLEWARD OUTFLOW CHANNEL OVER THE NEXT 24 HOURS. THE ONLY POSSIBLE HINDRANCE WILL BE THE POSSIBILITY OF AN EYEWALL REPLACEMENT CYCLE (EWRC) AT SOME POINT IN THE NEXT DAY AND A HALF. CURRENTLY, THERE ARE NO INDICATIONS IN THE CIMSS M-PERC PRODUCT OF AN EWRC, BUT WITH THE SYSTEM SOON TO REACH SUPER TYPHOON STRENGTH, IT IS LIKELY AN EWRC WILL BE IN THE OFFING AT SOME POINT. IN THE MEANTIME, THE SYSTEM IS FORECAST TO REACH AT LEAST 145 KNOTS BY TAU 36 AND THE TRUE PEAK COULD POTENTIALLY BE EVEN HIGHER IF IT CAN GET THERE BEFORE AN EWRC STARTS. BY TAU 48, SHEAR BEGINS TO REAR ITS HEAD ONCE MORE, SLOWLY AT FIRST AND THEN ALL AT ONCE. ROBUST POLEWARD OUTFLOW INTO THE DIVERGENT TROUGH WILL OFFSET THE INITIAL INCREASE IN SHEAR FOR THE MOST PART AND THE WEAKENING WILL INITIALLY BE SLOW. BY TAU 72, SHEAR IS EXPECTED TO EXCEED 30 KNOTS AND USHER IN DRY MID-LEVEL AIR AT THE SAME TIME, MARKING THE ONSET OF RAPID WEAKENING. BETWEEN TAU 72 AND TAU 96 THE SYSTEM BEGINS EXTRATROPICAL TRANSITION (ETT), AS IT SHALLOWS OUT AND BECOMES MORE ASYMMETRICAL. HOWEVER, THE SYSTEM IS NOT CURRENTLY EXPECTED TO TRANSITION TO A COLD-CORE LOW, BUT RATHER COMPLETE ETT AS A TYPHOON-STRENGTH WARM CORE SECLUSION BY TAU 120. MODEL DISCUSSION: TRACK GUIDANCE IS IN VERY GOOD AGREEMENT, WITH MINIMAL CROSS- OR ALONG-TRACK SPREAD THROUGH TAU 72. CROSS-TRACK SPREAD WIDENS TO 270NM AND ALONG-TRACK SPREAD INCREASES TO 470NM BY TAU 120. THE JTWC FORECAST LIES CLOSE TO THE CONSENSUS MEAN THROUGH TAU 96, THEN SHIFTS A BIT SOUTH AND SLOWER THAN THE MEAN THROUGH TAU 120. CONFIDENCE IN THE TRACK IS HIGH TO TAU 72 AND MEDIUM THEREAFTER. INTENSITY GUIDANCE IS IN GOOD AGREEMENT, DEPICTING FURTHER RI TO TAU 48, WHERE THE HAFS-A, COAMPS-TC AND RIPA AGREE ON A PEAK OF 145 KNOTS. AS MENTIONED ABOVE, A PEAK OF UP TO 10 KNOTS HIGHER IS A DISTINCT POSSIBILITY IF THE START OF AN EWRC IS DELAYED. THE JTWC FORECAST TRACKS THE RI GUIDANCE TREND AND IS ABOVE THE CONSENSUS MEAN THOUGH TAU 48, AND THEN FOLLOWS THE CONSENSUS MEAN THROUGH THE END OF THE FORECAST. CONFIDENCE IS HIGH IN THE NEAR-TERM, BUT LOW AFTER TAU 48. FORECAST CONFIDENCE: TRACK 0 - 72 HR: HIGH TRACK 72-120 HR: MEDIUM INTENSITY 0 - 72 HR: HIGH INTENSITY 72-120 HR: LOW// NNNN