Typhoon 05W(DOKSURI) to make landfall near XIAMEN/CHINA shortly before 24h//TD 06W forecast to reach CAT 4 US by 96h//2709utc

JTWC IS ISSUING 6HOURLY WARNINGS AND 3HOURLY SATELLITE BULLETINS ON TY 05W(DOKSURI) AND TD 06W.

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) AND A RECENT 270530Z AMSR2 89GHZ MICROWAVE IMAGE INDICATES THAT TYPHOON (TY) 05W (DOKSURI) IS IN THE MIDST OF ANOTHER EYEWALL REPLACEMENT CYCLE (ERC), WITH A SMALL (35NM) INNER CORE OF DEEP CONVECTION WITH A NASCENT PINHOLE EYE, SURROUNDED BY A MOAT AND AN OUTER EYEWALL OUT 55NM TO 70NM FROM THE CENTER. THE ANIMATED MSI SHOWS THAT DEEP CONVECTION AND VORTICAL HOT TOWERS (VHTS) ARE RAPIDLY CONSOLIDATING AROUND THE DEVELOPING EYE WHILE THE OUTER EYEWALL REMAINS FAIRLY ROBUST AS WELL. COMPARISON OF THE AMSR2 IMAGERY WITH AN EARLIER ATMS 88GHZ IMAGE SUGGESTS THE OUTER EYEWALL IS ALREADY STARTING TO SHRINK DOWN. ANALYSIS OF CWB RADAR IMAGERY SHOWS THAT THE SYSTEM TOOK A SHARP WESTWARD TURN FROM APPROXIMATELY 0000Z-0300Z, BEFORE TURNING NORTHWARD AGAIN. THE INITIAL POSITION IS ASSESSED WITH HIGH CONFIDENCE BASED ON THE PINHOLE EYE IN BOTH THE MSI AND THE AMSR2 IMAGE. IN TERMS OF INTENSITY, THE BULK OF THE OBJECTIVE ESTIMATES ARE STRUGGLING WITH THE SMALL NATURE OF THE INNER CORE AND THUS ARE SIGNIFICANTLY TOO LOW. THE DMINT HOWEVER IS 80 KNOTS, AND SATCON IS AROUND 75 KNOTS, BOTH OF WHICH SUPPORT EARLIER 272200Z SENTINEL-1 AND RCM-3 SAR MEASUREMENTS OF 79 KNOTS. THE TURN WAS SHARP ENOUGH TO WARRANT AN INTERMEDIATE 0300Z POSITION. ANALYSIS REVEALS THE SYSTEM IS MOVING INTO AN AREA OF LOW (5-10 KNOTS) VWS AND IS STARTING TO TAP INTO A POLEWARD OUTFLOW CHANNEL INTO AN UPPER-LEVEL LOW PARKED WEST OF SHANGHAI, IN ADDITION TO THE ALREADY STRONG EQUATORWARD CHANNEL. SSTS ARE INCREASING AS THE SYSTEM EXITS THE AREA OF UPWELLING NORTH OF LUZON, AND AS THE SYSTEM APPROACHES THE SHALLOW COAST OF CHINA, COASTAL DOWNWELLING WILL LIKELY RESULT IN INCREASED SSTS AND OHC RIGHT ALONG THE COAST. BOTH THE RADIUS OF MAXIMUM WINDS (RMW) AND THE 34 KNOT WIND RADII HAVE BEEN REDUCED BASED ON ANALYSIS OF SAR AND ASCAT DATA.

TYPHOON (TY) 05W (DOKSURI) IS IN THE MIDST OF ANOTHER EYEWALL REPLACEMENT CYCLE (ERC),

FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: THROUGH THE NEXT FEW HOURS, THE COMBINED INFLUENCE OF THE ERC AND SOME LINGERING EFFECTS FROM THE PROXIMITY OF TAIWAN, TY 05 IS LIKELY TO CONTINUE TO WOBBLE A BIT, THOUGH TRACK GENERALLY TOWARDS THE NORTHWEST UNDER THE GENERAL STEERING INFLUENCE OF THE STRONG STR TO THE NORTHEAST. THE SYSTEM IS EXPECTED TO MAKE LANDFALL ALONG THE CHINESE COAST IN THE VICINITY OF XIAMEN, CHINA BY AROUND TAU 18. AS DISCUSSED ABOVE, SEVERAL FACTORS ARE AT PLAY THAT WILL INFLUENCE THE INTENSITY FORECAST. FIRST, THE SYSTEM IS TAPPING INTO A STRONG POLEWARD OUTFLOW CHANNEL INTO AN UPPER-LEVEL LOW WEST OF SHANGHAI, PROVIDING ADDITIONAL OUTFLOW TO THE ALREADY EXISTING STRONG EQUATORWARD OUTFLOW CHANNEL. THOUGH THE UPPER-LEVEL LOW WILL FILL OVER THE NEXT 24 HOURS, OUTFLOW WILL CONTINUE FLOWING NORTHWARD LONG ENOUGH TO SUPPORT INTENSIFICATION PRIOR TO LANDFALL. ADDITIONALLY, THE WARM SSTS ALREADY IN PLACE ALONG THE COAST OF CHINA WILL LIKELY INCREASE AS THE STORM APPROACHES DUE TO COASTAL DOWNWELLING, PROVIDING A BOOST IN ENERGY TO SUPPORT INTENSIFICATION. LASTLY, AS THE SYSTEM MOVES CLEAR OF TAIWAN AND INTO THE SOUTHERN END OF THE TAIWAN STRAIT, SOME FUNNELING AND FRICTIONAL EFFECTS WILL HELP SUPPORT A DECREASE IN THE OUTER EYEWALL, ALSO SUPPORTING INTENSIFICATION. THE NET EFFECT WILL BE A FORECASTED INCREASE TO AT LEAST 90 KNOTS BY TAU 12, WITH A POTENTIAL HIGHER PEAK OCCURRING JUST PRIOR TO LANDFALL AROUND TAU 18. AFTER LANDFALL, TY 05W WILL TRAVEL NORTH-NORTHWESTWARD ALONG THE WEST SIDE OF THE STEERING RIDGE, ULTIMATELY DISSIPATING WEST OF SHANGHAI BY TAU 48.

MODEL DISCUSSION: AVAILABLE TRACK GUIDANCE IS IN VERY TIGHT AGREEMENT ON THE NORTH-NORTHWEST TRACK THROUGH THE FORECAST PERIOD BUT CANNOT CAPTURE THE LIKELY NEAR-TERM WOBBLES IN THE TRACK DISCUSSED ABOVE. TRACK SPEEDS WILL BE RELATIVELY SLOW FOR THE FIRST 12 HOURS AS THE WOBBLES SLOW THE EFFECTIVE FORWARD SPEED, BUT TRACK SPEEDS PICK UP FROM THERE THROUGH LANDFALL. THE JTWC FORECAST IS CONSISTENT WITH THE PREVIOUS FORECAST, AND LIES NEAR THE CONSENSUS MEAN WITH HIGH CONFIDENCE. THE INTENSITY GUIDANCE IS ALSO IN GOOD AGREEMENT, BUT WITH THIS RUN THE BULK OF THE GUIDANCE HAS BACKED OFF NEAR-TERM INTENSIFICATION, WITH THE EXCEPTION OF COAMPS-TC (GFS). THE JTWC FORECAST DEVIATES FROM THE GUIDANCE IN INTENSIFYING THE SYSTEM PRIOR TO LANDFALL BUT THEN REJOINS THE PACK THROUGH THE REMAINDER OF THE FORECAST. CONFIDENCE IS THUS MEDIUM THROUGH THE FORECAST PERIOD.

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A BROAD CIRCULATION WITH FRAGMENTED AND DISORGANIZED CONVECTION FIRING OFF, BUT UNABLE TO PERSIST AT THIS TIME. A 262353Z ASCAT-C SCATTEROMETER PASS REVEALED A BROAD LOW LEVEL CIRCULATION CENTER (LLCC) WITH 20-25 KNOTS WINDS PRESENT IN ALL QUADRANTS, BUT WITH A RADIUS OF MAXIMUM WINDS (RMW) OF ABOUT 80NM. SUBSEQUENT AMSR2 WINDSPEED PRODUCTS INDICATED A SIMILAR ARRANGEMENT, WITH AN RMW OF ABOUT 70NM AND 25-30 KNOT WINDS LIMITED TO THE NORTHEAST QUADRANT. A 270613Z SSMIS COLOR ENHANCED 91GHZ MICROWAVE IMAGE REVEALED WELL DEFINED LOW-LEVEL BANDS BUT ONLY FRAGMENTED AREAS OF MODERATE CONVECTION. THE MICROWAVE IMAGERY AND ANIMATED MSI PROVIDED MEDIUM CONFIDENCE IN THE INITIAL POSITION. THE INITIAL INTENSITY IS ASSESSED WITH HIGH CONFIDENCE BASED ON A T1.5 DVORAK ESTIMATE FROM RJTD AND A T1.0 FROM PGTW AS WELL AS THE AFOREMENTIONED, AMSR2 AND SCATTEROMETER DATA. THE SYSTEM IS CURRENTLY TRACKING NORTHWESTWARD ALONG THE SOUTHWEST PERIPHERY OF A LOW TO MID-LEVEL NEAR-EQUATORIAL RIDGE (NER) CENTERED TO THE EAST OF THE MARIANAS. OVERALL, THE ENVIRONMENT IS CURRENTLY CHARACTERIZED AS MARGINALLY FAVORABLE, WITH VERY WARM (30-31C) SSTS AND MODERATE EQUATORWARD OUTFLOW. THE PRIMARY LIMITING FACTORS AT PRESENT ARE THE BROAD NATURE OF THE LLC AND THE NORTHERLY FLOW EMANATING FROM TY 05W PUSHING DOWN FROM THE NORTH. HOWEVER, THE SYSTEM LIES RIGHT UNDER THE INFLECTION POINT WHERE THE OUTFLOW FROM TY 05W SPLITS, AND THEREFORE SHEAR HAS LESSENED A BIT.

FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THIS INITIAL PROGNOSTIC REASONING MESSAGE ESTABLISHES THE FORECAST PHILOSOPHY. FORECAST DISCUSSION: TD 06W (SIX) IS EXPECTED TO MOVE TOWARDS THE WEST-NORTHWEST FOR THE NEXT 24 HOURS UNDER THE INFLUENCE OF THE LOW TO MID-LEVEL FLOW ASSOCIATED WITH THE NER CENTERED EAST OF THE MARIANAS. AROUND TAU 24, THE SYSTEM IS EXPECTED TO TURN MORE POLEWARD AS THE NER TO THE EAST STRENGTHENS AND MOVES WEST AND ALIGNS TO A MORE NORTH-SOUTH AXIS. BY AROUND TAU 72, THE NER WEAKENS AND BEGINS TO SLIDE SOUTHWESTWARD, AND TD 06W RUNS SMACK INTO THE VERY STRONG SUBTROPICAL RIDGE (STR) CENTERED NEAR TOKYO. THIS WILL FORCE THE SYSTEM TO TURN LEFT ONTO A MORE WEST-NORTHWESTWARD TRACK FROM TAU 72 THROUGH TO THE END OF THE FORECAST PERIOD AS THE PRIMARY STEERING INFLUENCE SHIFTS TO THE STR TO THE NORTH. THROUGH THE NEXT 36 HOURS, TD 06W WILL SLOWLY BUT STEADILY CONSOLIDATE, AND THE RMW WILL STEADILY REDUCE. DUE TO THE MARGINAL OUTFLOW ENVIRONMENT AND MODEST AMOUNTS OF NORTHERLY SHEAR, THE SYSTEM WILL INTENSIFY AT A SLOW RATE, REACHING 40 KNOTS BY TAU 36. AROUND TAU 48 HOWEVER, THE ENVIRONMENT WILL RAPIDLY BECOME MORE FAVORABLE. AS EARLY AS TAU 24, A TUTT-CELL BEGINS TO DEVELOP BETWEEN TWO VERY STRONG UPPER-LEVEL ANTICYCLONES, IN THE VICINITY 25N 140E. BUT THROUGH THE FIRST 36 HOURS OF THE FORECAST, THE TUTT IS IN AN UNFAVORABLE POSITION FOR TD 06W. BETWEEN TAU 48 AND 72 THE TUTT MOVES INTO A HIGHLY FAVORABLE POSITION TO THE NORTHWEST OF TD 06W, AND THE SYSTEM WILL TAP INTO THE VERY STRONG POLEWARD OUTFLOW CHANNEL INTO THE EASTERN SIDE OF THE STRONG TUTT-CELL, SUPPORTING EXPLOSIVE INTENSIFICATION AFTER TAU 48, TO A PEAK OF AT LEAST 115 KNOTS, THOUGH A THE POTENTIAL FOR A MUCH HIGHER PEAK CANNOT BE RULED OUT, IN THE TAUS BETWEEN THE FORECAST POINTS. AFTER TAU 96, THE SYSTEM MOVES INTO AN AREA OF SLIGHTLY LESS UPPER-LEVEL OUTFLOW AND WILL LIKELY MAINTAIN INTENSITY AFTER PASSING VERY CLOSE TO OR OVER THE ISLAND OF OKINAWA AND MOVING INTO THE EAST CHINA SEA.

MODEL DISCUSSION: DETERMINISTIC TRACK GUIDANCE IS IN GOOD AGREEMENT, WITH THE CONSENSUS MEMBERS CONTAINED WITHIN A 100NM ENVELOPE AT TAU 72 WHICH GRADUALLY EXPANDS TO JUST 150NM BY TAU 120. AVAILABLE ENSEMBLE GUIDANCE IS ALSO CONSTRAINED TO A FAIRLY TIGHT, THOUGH SLIGHTLY LARGER THAN THE DETERMINISTIC, ENVELOPE CENTERED ON OKINAWA. THE JTWC FORECAST LIES WEST AND SOUTH OF THE CONSENSUS MEAN THROUGH THE FIRST 24 HOURS, THEN CLOSELY TRACKS THE GFS AND CONSENSUS MEAN THROUGH THE REMAINDER OF THE FORECAST. CONFIDENCE IN THE FIRST 72 HOURS OF THE TRACK IS MEDIUM DUE TO THE FACT THAT THE BROAD NATURE OF THE LLC INDUCES UNCERTAINTY IN THE INITIAL POSITION AND THUS THE FIRST STAGES OF THE FORECAST. CONFIDENCE REMAINS MEDIUM IN THE LONG-RANGE TRACK FOR THE SAME REASON. INTENSITY GUIDANCE IS IN GOOD AGREEMENT BUT IS INTENSIFYING THE SYSTEM TOO FAST IN THE FIRST 48 HOURS AND NOT ENOUGH IN THE LATER TAUS. THE JTWC FORECAST LIES 5-10 KNOTS BELOW THE CONSENSUS MEAN THROUGH TAU 48, THEN GOES WELL ABOVE THE MEAN AFTER TAU 72. THE FORECAST MOST CLOSELY FOLLOWS THE HWRF AND CTR1 SOLUTION AFTER TAU 48, AND PEAKS 30 KNOTS HIGHER THAN THE CONSENSUS MEAN, WHICH IS BEING HELD TOO LOW BY THE HAFS-A AND GFS MESOSCALE GUIDANCE. ADDITIONALLY, THE COAMPS-TC ENSEMBLE RAPID INTENSIFICATION (RI) PROBABILITY GUIDANCE, SHOWS A 50 PERCENT PROBABILITY OF RI BETWEEN TAU 54 AND TAU 90, PROVIDING ADDITIONAL CONFIDENCE IN THE FORECAST ABOVE THE CONSENSUS MEAN, BUT CONFIDENCE REMAINS LOW IN THE LATER TAUS DUE TO THE UNCERTAINTY IN THE EARLY PORTION OF THE FORECAST AND HOW LONG IT TAKES THE SYSTEM TO ORGANIZE AND REACH TROPICAL STORM STRENGTH.