Typhoon 14W(KOINU) CAT 3 US defies forecasts//Invest 98W Tropical Cyclone Formation Alert//Invest 97W//TS 15E(LIDIA)//0609utc

JTWC IS ISSUING 6HOURLY WARNINGS AND 3HOURLY SATELLITE BULLETINS ON TY 14W(KOINU). 3HOURLY SATELLITE BULLETINS ARE ISSUED ON INVEST 98W.

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS TYPHOON (TY) 14W RAPIDLY INTENSIFYING, TIGHTENING IN HORIZONTAL STRUCTURE AND EXPOSING A CLEAR, VERY SYMMETRIC EYE OF 10NM DIAMETER. THE HIGHLY FAVORABLE ENVIRONMENT WAS REALIZED BY TY 14W, WHICH TOOK FULL ADVANTAGE OF THE WARM SEA SURFACE TEMPERATURES (29-30 DEGREES CELSIUS) AND LOW VERTICAL WIND SHEAR (5-10KTS). A 060600Z HIMAWARI-9 ENHANCED INFRARED IMAGE SHOWED THE COOLEST CLOUD TOPS TO BE VERY SYMMETRICALLY AND TIGHTLY DISPLACED JUST 30NM OUTWARD FROM THE CENTER OF THE EYE. THE COMPACT NATURE OF THE SYSTEM CERTAINLY AIDED IN THE RAPID INTENSIFICATION PROCESS. OVERSHOOTING CLOUD TOPS PERSIST, SUGGESTING INTENSIFICATION IS ONGOING. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON A 060600Z HIMAWARI-9 CIRA- PROXYVIS IMAGE SHOWING AN UNOBSCURED EYE. THE INITIAL INTENSITY OF 100 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON UNIFORM SUBJECTIVE DVORAK INTENSITY ESTIMATES AND OBJECTIVE INTENSITY ESTIMATES LISTED BELOW.

FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE HAS BEEN A SIGNIFICANT SHIFT IN THE FORECAST INTENSITY OF TY 14W SINCE THE PREVIOUS WARNING (027). THIS IS DUE TO THE UNFORESEEN OCCURRENCE OF RAPID INTENSIFICATION SINCE 060000Z. FORECAST DISCUSSION: TY 14W IS FORECAST TO TRACK WEST THROUGH TAU 48 WITH PARTICULARLY SLOW TRACK SPEEDS (2-4 KTS) FROM TAU 12 TO TAU 48 DUE TO A SUBTROPICAL RIDGE (STR) CENTERED OVER NORTHERN VIETNAM. FOLLOWING THIS ENCOUNTER, 14W IS EXPECTED TO FOLLOW THE STEERING INFLUENCE OF THE STR AND TURN SOUTHWESTWARD FROM TAU 48 TO TAU 72 AND MAINTAIN THIS HEADING THROUGH TAU 120. CLEARLY, THE SYSTEM IS IN A HIGHLY FAVORABLE ENVIRONMENT AND THE AFOREMENTIONED COMPACT STRUCTURE SEEMS TO BE KEEPING THE DRY AIR AHEAD OF TRACK OUT OF THE SYSTEM FOR THE TIME BEING. HOWEVER, TY 14 SLOWING DOWN AFTER TAU 12 WILL CAUSE DETRIMENTAL UPWELLING TO OCCUR, WHICH IS ANTICIPATED TO WEAKEN THE SYSTEM INTENSITY STARTING AT TAU 12. THE FORECAST CONFIDENCE FROM TAU 00 TO TAU 72 FOR BOTH TRACK AND INTENSITY IS MEDIUM, AND LOW THEREAFTER.

MODEL DISCUSSION: GLOBAL NUMERICAL MODEL GUIDANCE IS IN EXCEPTIONAL AGREEMENT THAT TY 14W WILL CONTINUE ON A WESTWARD TRACK THROUGH TAU 48 AND THEN GRADUALLY TURN SOUTHWESTWARD AND MAINTAIN TRACK THROUGH TAU 120. HOWEVER, THE TRACK SPEED SHOWS MODERATE UNCERTAINTY BY TAU 72 WITH AN ALONG-TRACK SPREAD OF 153NM. THE SAME UNCERTAINTY COMPOUNDS AT TAU 120, WITH AN ALONG-TRACK SPREAD OF 330NM AND A CROSS-TRACK SPREAD OF 240NM. BRIEFLY DISCUSSING THE RAPID INTENSIFICATION OCCURRENCE, THE ONLY INDICATIONS OF INTENSIFICATION PRESENTED IN THE OBJECTIVE AID INTENSITIES FOR THE PREVIOUS FORECAST WERE COAMPS-TC AND HAFS-A, EACH SUGGESTING JUST A 5 KNOT RISE IN INTENSITY. PRESENTLY, HAFS-A AND STATISTICAL-DYNAMICAL INTENSITY GUIDANCE REFLECT THE POSSIBILITY OF A 5 KNOT INCREASE BY TAU 12, ALONG WITH MULTIPLE RAPID INTENSIFICATION INDICATIONS TRIGGERED.

THE AREA OF CONVECTION (INVEST 98W) PREVIOUSLY LOCATED NEAR 8.0N 156.0E IS NOW LOCATED NEAR 8.8N 155.9E, APPROXIMATELY 715 NM EAST- SOUTHEAST OF GUAM. ANIMATED MULTISPECTRAL IMAGERY AND A PARTIAL 060739Z SSMIS 91GHZ MICROWAVE IMAGE DEPICT AN AREA OF DEEP CONVECTION DISPLACED TO THE NORTHWEST OF A MOSTLY OBSCURED LOW LEVEL CIRCULATION CENTER (LLCC). FORMATIVE SPIRAL BANDS OF DEP CONVECTION ARE OBSERVED WRAPPING INTO THE NORTHWEST QUADRANT OF THE SYSTEM. ENVIRONMENTAL ANALYSIS REVEALS THAT 98W IS IN A FAVORABLE ENVIRONMENT FOR INTENSIFICATION DUE TO WARM (30C) SST, GOOD DUAL-CHANNEL OUTFLOW, AND LOW (5-10 KTS) VERTICAL WIND SHEAR (VWS). GLOBAL MODELS ARE IN GOOD AGREEMENT THAT THE VORTEX WILL CONTINUE TO CONSOLIDATE OVER THE NEXT 12-24 HOURS WHILE IT TRACKS GENERALLY WEST-NORTHWESTWARD. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 17 TO 22 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1006 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS HIGH.

AN AREA OF CONVECTION (INVEST 97W) HAS PERSISTED NEAR 13.6N 140.5E, APPROXIMATELY 246 NM WEST OF ANDERSEN AFB, GUAM. ANIMATED MULTISPECTRAL IMAGERY AND A 060020Z ASCAT METOP-C IMAGE DEPICTS A BROAD PARTIALLY OBSCURED LOW LEVEL CIRCULATION WITH BUILDING CONVECTION OVERHEAD AND TO THE SOUTHEAST, ALSO SHOWN IN A 060151Z GMI 89GHZ SATELLITE MICROWAVE IMAGE. ENVIRONMENTAL ANALYSIS INDICATES THAT 97W IS IN A FAVORABLE ENVIRONMENT FOR DEVELOPMENT WITH CONVERGENCE IN THE LOWER LEVELS TO THE WEST, DIVERGENCE ALOFT TO THE SOUTHEAST LOW COUPLED WITH WESTWARD OUTFLOW, LOW VWS (5-10KTS) AND WARM (29-30C) SST. GLOBAL MODELS AGREE THAT 97W WILL TRACK WESTWARD, AND CONTINUE TO CONSOLIDATE OVER THE NEXT 48 HOURS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 18 TO 22 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1007 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS LOW.