03W(GUCHOL) intensifying peaking at Typhoon CAT 2US within 48h// 02A(BIPARJOY) RI past 24h peaking at CAT 3 US within 48h//0703utc

JTWC IS ISSUING 6HOURLY WARNINGS AND 3HOURLY SATELLITE BULLETINS ON TS 03W(GUCHOL) AND ON TC 02A(BIPARJOY).

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A STEADILY, ALBEIT SLOWLY, CONSOLIDATING SYSTEM WITH FRAGMENTED CONVECTIVE BURSTS STRUGGLING TO MAINTAIN AND WRAP AROUND THE LOW LEVEL CIRCULATION CENTER (LLCC). SIMILAR TO SIX HOURS AGO, DEEP CONVECTIVE TOWERS CONTINUE TO FLARE UP AROUND THE LLCC BUT NONE HAVE YET BEEN ABLE TO SUSTAIN THEMSELVES FOR MORE THAN AN HOUR TO TWO. THUS, THE INNER CORE, WHILE IMPROVING, REMAINS SOMEWHAT DISORGANIZED AND TRUE INTENSIFICATION HAS YET TO BEGIN. THE MOST RECENT MICROWAVE IMAGE FROM 062009Z INDICATED A BROAD SWATH OF DEEP CONVECTION LAYING IN A BAND ACROSS THE SOUTHERN HALF OF THE SYSTEM, BUT LITTLE IN THE WAY OF ORGANIZED CONVECTIVE ACTIVITY IN THE NORTHERN HEMISPHERE, DUE TO THE PRESENCE OF DRY AIR IN THE MID-LEVELS TO THE NORTH. THE INITIAL POSITION IS ASSESSED WITH MEDIUM CONFIDENCE AS THE PRECISE LLCC IS OBSCURED BUT ANALYSIS OF THE OUTER BANDS PROVIDES SOME HINT AS TO THE CENTER. THE INITIAL INTENSITY IS ALSO ASSESSED WITH MEDIUM CONFIDENCE, HEDGED SLIGHTLY HIGHER THAN THE MULTI-AGENCY DVORAK CURRENT INTENSITY ESTIMATES IN LIGHT OF AN ADT ESTIMATE OF 43 KNOTS AND THE GENERALLY IMPROVING STRUCTURE. THE ENVIRONMENT REMAINS FAVORABLE, CHARACTERIZED BY LOW VWS, WARM SSTS, HIGH OHC AND GOOD EASTWARD AND EQUATORWARD OUTFLOW INTO A TUTT CELL LOCATED NEAR 19N 150E. THE SYSTEM HAS SLOWED DOWN TO JUST TWO KNOTS AND TURNED MORE WESTWARD AS IT BUTTS UP AGAINST AN EXTENSION OF THE SUBTROPICAL RIDGE (STR) THAT EXTENDS FROM TAIWAN TO 30N 175E.

FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TS 03W HAS SLOWED DOWN AND TURNED A BIT FURTHER TOWARDS THE WEST, AS THE NARROW RIDGE TO THE NORTH HAS STRENGTHENED A BIT BASED ON THE LATEST SOUNDING FROM MINAMI DAITO JIMA. BUT OTHER THAN THAT NEAR-TERM ADJUSTMENT, NO OTHER SIGNIFICANT CHANGES TO THE STEERING PATTERN ARE EXPECTED AND THE SYSTEM WILL TRACK SLOWLY TOWARDS THE WEST-NORTHWEST THROUGH THE NEXT 36 TO 48 HOURS ALONG THE SOUTHERN SIDE OF THE RIDGE TO THE NORTH. THE PASSAGE OF A STRONG SHORTWAVE TROUGH AND JET MAX OVER JAPAN AROUND TAU 48 WILL BREAK THE RIDGE TO THE NORTH WHILE ALSO BUILDING A NEW STR CENTER NEAR 30N 155E. THIS COMBINATION OF EVENTS WILL ALLOW FOR TS 03W TO TURN NORTHWARD 72, THEN ACCELERATE NORTHEASTWARD ALONG THE WESTERN SIDE OF THE BUILDING STR TO THE EAST THROUGH THE REMAINDER OF THE FORECAST PERIOD. CONTINUED GOOD ENVIRONMENTAL CONDITIONS; OUTFLOW INTO THE TUTT CELL TO THE EAST, LOW VWS AND WARM SSTS, WILL FUEL RAPID INTENSIFICATION (RI) THROUGH TAU 36, TO A PEAK OF 85 KNOTS, ASSUMING THE INNER CORE OF THE SYSTEM CAN CONSOLIDATE QUICKLY. AFTER TAU 48, A REDUCTION IN UPPER-LEVEL OUTFLOW, AND SOME INCREASED PRESSURE FROM A PUNCH OF NORTHWESTERLY FLOW WILL LEAD TO A PERIOD OF STAGNANT INTENSITY THROUGH TAU 72. THEREAFTER, OUTFLOW INTO THE BASE OF THE UPPER-LEVEL TROUGH TO THE NORTH WILL OFFSET INCREASED VWS AND DECREASING SSTS, ALLOWING FOR A VERY SLOW STEP-DOWN IN INTENSITY AS THE SYSTEM ACCELERATES NORTHEASTWARD THROUGH THE REMAINDER OF THE FORECAST.

MODEL DISCUSSION: TRACK GUIDANCE REMAINS IN GOOD AGREEMENT ON THE OVERALL RECURVE SCENARIO AND SPREAD IS A BIT LESS THAN IN THE PREVIOUS RUN BUT AS IS NORMAL WITH A RECURVE SCENARIO, THERE REMAINS A FAIR AMOUNT OF CROSS-TRACK SPREAD THROUGH THE TURN. THE EUROPEAN MODELS CONTINUE TO SHOW A WIDER TURN, REACHING FURTHER TO THE WEST, WHILE THE US MODELS LIE ON THE OPPOSITE SIDE OF THE ENVELOPE. THE JTWC FORECAST STILL HEDGES TOWARDS THE US MODELS BUT STILL LIES WEST OF THEIR TRACKERS. CONFIDENCE IS HIGH THROUGH THE FIRST 48 HOURS, DECREASING TO MEDIUM THEREAFTER DUE TO THE INCREASED SPREAD THROUGH AND AFTER THE TURN POLEWARD. INTENSITY GUIDANCE HAS STARTED TO COME INTO BETTER AGREEMENT WITH ALL MEMBERS OF THE CONSENSUS NOW AGREEING ON A FAIRLY RAPID INTENSIFICATION TREND THROUGH TAU 48, FOLLOWED BY A SLOW WEAKENING TREND. SEVERAL RI AIDS CONTINUE TO TRIGGER AND BRING THE CONSENSUS MEAN UP TO ABOUT 80 KNOTS. THE JTWC FORECAST GOES A BIT HIGHER, TO 85 KNOTS, IN LINE WITH THE BULK OF THE RI GUIDANCE, THEN RESUMES THE CONSENSUS MEAN BY TAU 96.

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS BANDS OF PULSING CONVECTION, FIRING OFF TO THE SOUTHWEST OF THE LOW LEVEL CIRCULATION CENTER (LLCC) AND WRAPPING UPSHEAR TO THE EAST. ANIMATED IMAGERY FROM THE 0200Z HOUR HOWEVER SUGGESTS THAT THE MOST RECENT CONVECTIVE BURST HAS COLLAPSED, CLOUD TOP TEMPERATURES HAVE WARMED CONSIDERABLY AND THE MESOSCALE UPPER-LEVEL OUTFLOW FRONT HAS BEEN PUSHED BACK TOWARDS THE CORE OF THE SYSTEM. ANOTHER ROUND OF NASCENT CONVECTIVE TOWERS IS FLARING AGAIN ALONG THE SOUTHERN SIDE OF THE CENTER, BUT IT REMAINS TO BE SEEN WHAT IMPACT THIS WILL HAVE AS CONVECTIVE MAXIMUM APPROACHES. A TIMELY 062320Z SSMIS 91GHZ MICROWAVE IMAGE REVEALED A SMALL MICROWAVE EYE FEATURE, WITH A WIDE EXPANSE OF CONVECTIVE BANDS EXTENDING TO THE SOUTHWEST, BUT ONLY MINIMAL CONVECTIVE BANDING TO THE NORTHERN SIDE. THE INITIAL POSITION IS ASSESSED WITH HIGH CONFIDENCE BASED ON THE ABOVE MENTIONED MICROWAVE IMAGERY. MEANWHILE THE INITIAL INTENSITY IS ASSESSED WITH HIGH CONFIDENCE, HEDGED HIGHER THAN THE DVORAK CURRENT INTENSITY ESTIMATES BASED ON A PGTW DATA-T OF T4.5 (77 KNOTS), SUPPORTED BY THE ADT AND AIDT ESTIMATES OF 75 KNOTS AND 72 KNOTS RESPECTIVELY AND A DMINT ESTIMATE OF 71 KNOTS. MODERATE TO HIGH EASTERLY SHEAR IS PUTTING A BRAKE ON RAPID DEVELOPMENT, AS CONVECTION WILL PULSE AND PUSH BACK AGAINST THE SHEAR, THEN COLLAPSE AND START THE PROCESS ONCE MORE. OTHERWISE, CONDITIONS ARE GENERALLY FAVORABLE WITH VERY WARM SSTS, HIGH OHC AND GOOD EQUATORWARD AND POLEWARD OUTFLOW. THE SYSTEM CONTINUES TO DRIFT SLOWLY POLEWARD, WITH AN EXTENSION OF THE SUBTROPICAL RIDGE (STR) ALONG 20N BLOCKING SIGNIFICANT POLEWARD MOVEMENT FOR THE MOMENT.

FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TC 02A CONTINUES TO DRIFT VERY SLOWLY TOWARDS THE NORTH-NORTHEAST UNDER A BLOCKING PATTERN, WITH A FAIRLY ROBUST DEEP-LAYER RIDGE EXTENSION LYING ACROSS ITS PATH TO THE NORTH. AS A MID-LATITUDE TROUGH PUSHES EAST INTO NORTHERN INDIA OVER THE NEXT 12 TO 24 HOURS, THE BLOCKING RIDGE TO THE NORTH IS EXPECTED TO ERODE AND ULTIMATELY BREAK. AT THE SAME TIME, A NEW DEEP-LAYER RIDGE IS EXPECTED TO DEVELOP OVER SOUTHERN INDIA BY TAU 24, WHICH WILL BUILD STEADILY NORTH AND NORTHWESTWARD THROUGH THE REMAINDER OF THE FORECAST PERIOD. THE NET EFFECT OF THESE CHANGES IN THE STEERING PATTERN WILL BE THAT TC 02A DRIFTS SLOWLY NORTHWARD THROUGH ABOUT TAU 36, THEN WILL PICK UP SOME SPEED AND SLOWLY BUT STEADILY LEAN OVER TO THE LEFT, ENDING UP ON A NORTH-NORTHWESTWARD TRACK BY THE END OF THE FORECAST PERIOD. THE INTENSITY FORECAST IS ENTIRELY DEPENDENT UPON THE ABILITY OF THE DEEP CONVECTION TO CONTINUE TO WRAP UPSHEAR, BUT MORE IMPORTANTLY, THE SUSTAIN ITSELF THERE. ASSUMING THIS WILL BE ABLE TO HAPPEN AS WE APPROACH CONVECTIVE MAXIMUM, THE FORECAST CALLS FOR A PERIOD OF NEAR-RAPID INTENSIFICATION, TO A PEAK OF 100 KNOTS BY TAU 36. AFTER TAU 36, CHANGES TO THE UPPER-LEVEL PATTERN INDICATE THE SYSTEM WILL BE CUT OFF FROM THE EQUATORWARD OUTFLOW CHANNEL AND FOR AT TIME, OUTFLOW WILL BE SIGNIFICANTLY CONSTRAINED, LEADING TO A PERIOD OF STAGNANT INTENSITY THROUGH ABOUT TAU 48. THEREAFTER, AN EXPECTED INCREASE IN EASTERLY SHEAR AND DRY AIR ENTRAINMENT FROM THE ARABIAN PENINSULA WILL COMPOUND THE IMPACT OF THE REDUCED UPPER-LEVEL OUTFLOW, LEADING TO A MORE PRONOUNCED WEAKENING TREND THROUGH THE REMAINDER OF THE FORECAST PERIOD.

MODEL DISCUSSION: TRACK GUIDANCE IS COMING INTO BETTER AGREEMENT, AND THOUGH WHILE STILL BIFURCATED, THE SPREAD BETWEEN THE OUTLIERS HAS DECREASED WITH THIS RUN. THE GENERAL SCENARIO REMAINS THE SAME, WITH THE UKMET, GALWEM AND THEIR ENSEMBLES TAKING THE SYSTEM DUE NORTH THROUGH THE FORECAST PERIOD, WHILE THE GFS, NAVGEM, ECMWF, GEFS AND ECENS ALL TAKE THE SYSTEM MORE TOWARDS THE NORTHWEST. MEANWHILE THE HWRF AND COAMPS-TC MEMBERS ARE THE EXTREME OUTLIERS TO THE WEST, TAKING THE SYSTEM SHARPLY WESTWARD TOWARDS SALALAH. THE JTWC FORECAST IS CONSISTENT WITH THE ECMWF AND GFS SOLUTIONS AND LIES WEST OF THE CONSENSUS MEAN THROUGH THE ENTIRE FORECAST PERIOD, WITH MEDIUM CONFIDENCE. INTENSITY GUIDANCE REMAINS MIXED AND HAS BACKED OFF SIGNIFICANTLY SINCE THE PREVIOUS RUN. THE HWRF, COAMPS-TC (NAVGEM) AND MESOSCALE GFS ALL SHOW WEAKENING FROM TAU 00, WHILE THE SHIP AND RIPA, RICN AND DTOP RI AIDS ALL SHOW VARIOUS DEGREES OF INTENSIFICATION. THE MESOSCALE MODELS BEING SO LOW ARE BRINGING THE CONSENSUS DOWN TO BASICALLY STEADY STATE THROUGH THE FORECAST PERIOD. THE JTWC FORECAST LIES JUST SLIGHTLY BELOW THE RIPA GUIDANCE, AND PEAKS ABOUT 15 KNOTS HIGHER THAN THE CONSENSUS MEAN, THEN REMAINS ABOUT 10 KNOTS HIGHER THAN THE MEAN THROUGH THE WEAKENING PHASE. DUE TO THE SIGNIFICANT DISAGREEMENT BETWEEN THE VARIOUS INTENSITY CONSENSUS MEMBERS, THERE IS LOW CONFIDENCE IN THE JTWC INTENSITY FORECAST.