TC 11S(FREDDY): forecast RI up to CAT3 US by 48h//Invest 94S: intensification expected after recurvature//Invest 99P:up-graded//0615utc

JTWC IS ISSUING 6HOURLY WARNINGS ON TC 11S(FREDDY). 3HOURLY SATELLITE BULLETINS ARE ISSUED ON TC 11S, INVEST 94S AND INVEST 99P.

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: TROPICAL CYCLONE 11S, NOW NAMED FREDDY, HAS CONTINUED TO CONSOLIDATE AND RAPIDLY INTENSIFY UNDER FAVORABLE CONDITIONS. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY SHOWS A VERY COMPACT CENTRAL DENSE OVERCAST (CDO) FEATURE STARTING TO SEPARATE FROM AND BECOME MORE DISTINCT FROM THE STATIONARY BANDING COMPLEX (SBC) THAT IS TAILING OFF TO THE SOUTH OF THE CENTER. WHILE CONVECTION IS STILL SOMEWHAT DISORGANIZED AND THE HOT TOWERS HAVE YET TO ROTATE UPSHEAR, THE SYSTEM IS STILL COMING TOGETHER NICELY. A 061210Z AMSU-B 89GHZ MICROWAVE IMAGE REVEALED THE ASYMMETRIC NATURE OF THE CIRCULATION WITH A BAND OF DEEP CONVECTION WRAPPING UP THE WESTERN SIDE AND INTO THE DEVELOPING CORE, WITH A LARGE MOAT, DEVOID OF CONVECTION ENTRENCHED TO THE SOUTHEAST. THE INITIAL POSITION IS ASSESSED WITH MEDIUM CONFIDENCE AND IS PLACED JUST SOUTH OF THE CDO CENTROID AND AMONGST THE AGENCY FIX POSITIONS. THE INITIAL INTENSITY IS ASSESSED WITH HIGH CONFIDENCE BASED ON A CONGRUENCE OF THE BULK OF AGENCY FIXES, THE ADT, AND A 060946Z SMOS AND 060949Z SMAP WHICH SHOWED A MAX OF 39 KNOTS (CONVERTED TO 1-MIN). THE AIDT AND OTHER OBJECTIVE METHODS ARE QUITE A BIT LOWER, STRUGGLING WITH THE SMALL SIZE OF THE SYSTEM. THE ENVIRONMENT REMAINS HIGHLY FAVORABLE FOR CONTINUED RAPID INTENSIFICATION (RI) WITH JUICY SSTS (29-30C), LOW (0-10) VERTICAL WIND SHEAR (VWS) AND THE PRESENCE OF A SMALL POINT SOURCE ALOFT WHICH IS PROVIDING MODERATE RADIAL OUTFLOW TO THE SYSTEM.

FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TC FREDDY CONTINUES ITS RATHER IMPRESSIVE INTENSIFICATION TREND, HAVING BEEN A WEE LAD OF JUST 25 KNOTS ONLY 24 HOURS AGO. THE SYSTEM CONTINUES TO MOVE SLOWLY TOWARDS THE SOUTHWEST ALONG A WEAK STEERING GRADIENT ON THE NORTHWEST SIDE OF A BUILDING STR CENTERED ALONG THE WESTERN COAST OF AUSTRALIA. THE SYSTEM WILL TRACK IN A GRACEFUL ARC, BECOMING INCREASINGLY WEST-SOUTHWESTWARD THROUGH THE FIRST 48 HOURS. AFTER TAU 72, THE STR FLATTENS OUT AND MERGES INTO A LARGER RIDGE COMPLEX THAT EXTENDS ALONG ROUGHLY 25S FROM 90E TO CENTRAL AUSTRALIA, WHICH WILL RESULT IN A TRACK JUST SOUTH OF DUE WEST THROUGH THE REMAINDER OF THE FORECAST PERIOD. CONDITIONS REMAIN NEARLY OPTIMAL FOR CONTINUED RAPID INTENSIFICATION (RI). LATE RECEIPT OF A 061357Z GMI 37GHZ MICROWAVE IMAGE SUGGESTS THE SYSTEM IS STILL NOT VERTICALLY ALIGNED, WITH THE LOW LEVEL CIRCULATION CENTER (LLCC) DISPLACED TO THE SOUTHEAST OF THE CDO AND THE DEEP CONVECTIVE BANDS ARE NOT YET COMPLETELY ENCLOSING THE LLCC. WHILE THERE REMAINS WORK TO BE DONE TO FURTHER DEVELOP THE CORE, THIS DOES NOT CHANGE THE INTENSITY FORECAST. THE SYSTEM HAS ABOUT 48 HOURS WHERE ENVIRONMENTAL CONDITIONS WILL BE PRIME FOR RI. THE MESOSCALE POINT SOURCE ALOFT AND LOW SHEAR (LESS THAN 15 KTS) ARE EXPECTED TO PERSIST THROUGH TAU 48, WHILE THE SYSTEM MOVES OVER A HIGH OHC POOL BETWEEN TAU 24 TO 36. THESE CONDITIONS WILL FUEL RI TO A PEAK OF AT LEAST 100 KNOTS, THOUGH SOME MODELS SUGGEST AND EVEN HIGHER PEAK INTENSITY. SHEAR STARTS TO PICK UP AT TAU 48, AND AROUND TAU 60, HIGH RESOLUTION MODELS SUGGEST A PUNCH OF MID-LEVEL DRY AIR AND ELEVATED SHEAR WILL DISRUPT THE INNER CORE OF THE SYSTEM, WHICH WILL LEAD TO A SIGNIFICANT WEAKENING THROUGH TAU 72. CONDITIONS ARE EXPECTED TO IMPROVE AGAIN AFTER TAU 72, ENABLING REINTENSIFICATION THROUGH THE REMAINDER OF THE FORECAST PERIOD. SOME GUIDANCE SUGGESTS A MORE POLEWARD TRACK WHICH TAKES THE SYSTEM OVER COOL (24-26C) WATERS, WHICH IF BORNE OUT WILL LEAD TO STEADY WEAKENING AFTER TAU 96.

MODEL DISCUSSION: THROUGH THE FIRST 72 HOURS OF THE FORECAST, DETERMINISTIC AND ENSEMBLE TRACK GUIDANCE IS IN GOOD AGREEMENT, WITH ALL CONSENSUS MEMBERS ENCASED WITHIN A 70NM WIDE ENVELOPE, LENDING HIGH CONFIDENCE TO THE JTWC FORECAST TRACK IN THIS TIMEFRAME. AFTER TAU 72, THE MODELS ARE INDICATING THE BEGINNINGS OF A BIFURCATION, WITH THE NAVGEM, GFS, GEFS AND HWRF DEVIATING TO THE SOUTH, THE HWRF POSITIONING THE SYSTEM NEAR 20S AT TAU 120, WHILE THE ECMWF, ECENS, UKMET AND UKMET ENSEMBLE, TAKE THE SYSTEM ON A FLATTER TRAJECTORY ALONG 15S AND THE CONSENSUS SPLITS THE DIFFERENCE. THE JTWC FORECAST HEDGES TOWARDS THE US MODELS ON A MORE SOUTHERLY TRACK, WITH MEDIUM CONFIDENCE. INTENSITY GUIDANCE IS IN FAIRLY GOOD AGREEMENT AS WELL. RI AIDS INCLUDING CTR1, FRIA, RIPA, RICN AND THE BULK OF THE RI25-RI45 AIDS CONTINUE TO BE TRIGGERED. NOT SURPRISINGLY THE GLOBAL MODELS ARE LESS EXCITED ABOUT TC 11S, WITH PEAKS BELOW 75 KNOTS, WHILE THE MESOSCALE MODELS ARE MORE AGGRESSIVE AND SUPPORTIVE OF THE JTWC FORECAST. ALL MODELS SUGGEST A PEAK AROUND TAU 48, FOLLOWED BY WEAKENING AND EITHER A FLAT LINE OR SLIGHT INTENSIFICATION THEREAFTER. THE JTWC FORECAST IS CONSISTENT WITH THE RI AIDS THROUGH TAU 48 THOUGH PEAKS SLIGHTLY HIGHER THAN MOST, THEN TRACKS THE CONSENSUS MEAN THEREAFTER.

CONDITIONS REMAIN NEARLY OPTIMAL FOR CONTINUED RAPID INTENSIFICATION (RI).

AT 060200Z, THE AREA OF CONVECTION (INVEST 94S) PREVIOUSLY LOCATED NEAR 12.4S 95.8E IS NOW LOCATED NEAR 12.4S 97.7E, APPROXIMATELY 50 NM EAST-SOUTHEAST OF COCOS ISLANDS, AUSTRALIA. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) AND A 051903Z AMSR-2 MICROWAVE PASS SHOWS DEEP CONVECTION WRAPPING INTO A PARTIALLY EXPOSED AND RAPIDLY CONSOLIDATING LOW LEVEL CIRCULATION CENTER (LLCC). A 060130Z OBSERVATION FROM COCOS ISLANDS REVEALS WINDS OF 22 KTS FROM THE NORTHWEST. ENVIRONMENTAL CONDITIONS ARE GENERALLY FAVORABLE WITH LOW TO MODERATE (15-20 KTS) VWS AND WARM (29-30C) SST OFFSET BY STRONG POLEWARD AND EQUATORWARD OUTFLOW. GLOBAL MODELS CONCUR THAT INVEST 94S WILL CONTINUE EASTWARD FOR A SHORT PERIOD BEFORE RECURVING TO THE SOUTHWEST AND RAPIDLY INTENSIFY. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 20 TO 25 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1002 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS REMAINS MEDIUM.

ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) AND A 051903Z AMSR-2 MICROWAVE PASS SHOWS DEEP CONVECTION WRAPPING INTO A PARTIALLY EXPOSED AND RAPIDLY CONSOLIDATING LOW LEVEL CIRCULATION CENTER (LLCC).

GLOBAL MODELS CONCUR THAT INVEST 94S WILL CONTINUE EASTWARD FOR A SHORT PERIOD BEFORE RECURVING TO THE SOUTHWEST AND RAPIDLY INTENSIFY.

THE AREA OF CONVECTION (INVEST 99P) PREVIOUSLY LOCATED NEAR 12.5S 156.7E IS NOW LOCATED NEAR 12.4S 156.1E, APPROXIMATELY 461 NM EAST-NORTHEAST OF WILLIS ISLAND, AUSTRALIA. ANIMATED EIR AND A 061127Z AMSU-B 89GHZ MICROWAVE IMAGE DEPICT DEEP FLARING CONVECTION SURROUNDING A STILL DISORGANIZED LOW LEVEL CIRCULATION (LLC). ANALYSIS INDICATES INVEST 99P IS A IN FAVORABLE ENVIRONMENT FOR DEVELOPMENT WITH LOW (5-10KT) VWS, WARM (29-30C) SST, AND DECENT EQUATORWARD AND WEAK POLEWARD OUTFLOW SUPPORTED BY A POINT SOURCE TO THE WEST. ALL GLOBAL DETERMINISTIC AND ENSEMBLE MODELS AGREE THAT INVEST 99P WILL TRACK GENERALLY SOUTHWESTWARD OVER THE NEXT 48 HOURS WHILE STEADILY CONSOLIDATING AND INTENSIFYING. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 23 TO 27 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1002 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS UPGRADED TO MEDIUM.

ANIMATED EIR AND A 061127Z AMSU-B 89GHZ MICROWAVE IMAGE DEPICT DEEP FLARING CONVECTION SURROUNDING A STILL DISORGANIZED LOW LEVEL CIRCULATION (LLC).

ALL GLOBAL DETERMINISTIC AND ENSEMBLE MODELS AGREE THAT INVEST 99P WILL TRACK GENERALLY SOUTHWESTWARD OVER THE NEXT 48 HOURS WHILE STEADILY CONSOLIDATING AND INTENSIFYING.