TC 11S(FREDDY) peaked at CAT 5 US again now CAT 4 tracking North of Mauritius and Réunion islands//Invest 99W//Invest 93S//2003utc

JTWC IS ISSUING 12HOURLY WARNINGS AND 3HOURLY SATELLITE BULLETINS ON TC 11S(FREDDY).

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: AFTER PEAKING AT 140 KNOTS OR POTENTIAL A BIT HIGHER, FOR AN IMPRESSIVE FOURTH TIME IN ITS LIFE, TC 11S (FREDDY) HAS WEAKENED CONSIDERABLY OVER THE PAST 12 HOURS, AND IN PARTICULARLY IN THE LAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY AND CIMSS TC DIURNAL CLOCK CLOUD TOP CHANGE PRODUCTS DEPICT SIGNIFICANT WARMING OF THE CLOUD TOPS, PARTICULARLY ACROSS THE SOUTHERN HEMISPHERE OF THE STORM. AT THE SAME TIME, THE EYE TEMPERATURE HAS STARTED TO COOL SLIGHTLY, AFTER HAVING PEAKED NEAR +20C. THE FACT THAT THESE CHANGES ARE OCCURRING THROUGH THE DIURNAL CONVECTIVE MAXIMUM IS INDICATIVE OF OTHER PROCESSES INTERFERING WITH THE MAINTENANCE OF THE CORE OF THE SYSTEM. A 192313Z SSMIS 91GHZ IMAGE SHOWS A STATIONARY BANDING COMPLEX (SBC) DEVELOPING ACROSS THE SOUTHERN HEMISPHERE OF THE SYSTEM, LIKELY CONNECTING TO THE INNER EYEWALL ON THE NORTHWEST SIDE. THIS COULD POTENTIALLY MARK THE BEGINNING OF THE LONG-ANTICIPATED EYEWALL REPLACEMENT CYCLE (EWRC), AND THE FULL-MODEL M-PERC SHOWS AN INCREASING LIKELIHOOD OF EWRC IN THE NEXT 12 HOURS OR SO. EVEN WITHOUT AN EWRC, THE PRESENCE OF SBC IS USHERING IN SOME DRY MID-LEVEL AIR INTO THE CORE AND DISRUPTING THE ENERGY INFLOW, LEADING TO THE WEAKENING TREND SEEN OVER THE PAST 12 HOURS. THE INITIAL POSITION IS ASSESSED WITH HIGH CONFIDENCE BASED ON THE 25NM EYE IN THE EIR AND MICROWAVE IMAGE AND ON THE FIRST HINTS OF THE EYE ON THE MAURITIUS RADAR. THE INITIAL INTENSITY IS ASSESSED WITH HIGH CONFIDENCE BASED ON A BLEND OF SUBJECTIVE AND OBJECTIVE AGENCY DVORAK CURRENT INTENSITY ESTIMATES, HEDGED CLOSE TO THE CIMSS DEEP MICRONET AND OPEN-AIIR INTENSITY ESTIMATES. OVERALL, THE ENVIRONMENT REMAINS FAVORABLE, WITH MINIMAL SHEAR, WARM (THOUGH ABOUT A HALF DEGREE COOLER THAN 12 HOURS AGO) AND STRONG RADIAL OUTFLOW WITH THE ADDITION OF A POLEWARD OUTFLOW CHANNEL.

192313Z SSMIS 91GHZ IMAGE SHOWS A STATIONARY BANDING COMPLEX (SBC) DEVELOPING ACROSS THE SOUTHERN HEMISPHERE OF THE SYSTEM, LIKELY CONNECTING TO THE INNER EYEWALL ON THE NORTHWEST SIDE. THIS COULD POTENTIALLY MARK THE BEGINNING OF THE LONG-ANTICIPATED EYEWALL REPLACEMENT CYCLE (EWRC), AND THE FULL-MODEL M-PERC SHOWS AN INCREASING LIKELIHOOD OF EWRC IN THE NEXT 12 HOURS OR SO.

FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: NO MAJOR CHANGES IN THE TRACK ARE ANTICIPATED, AS THE SYSTEM TRAVERSES WEST-SOUTHWESTWARD ALONG THE NORTHERN SIDE OF STRONG STR TO THE SOUTH. TC 11S IS FORECAST TO PASS ABOUT 60-95NM NORTH OF BOTH MAURITIUS AND LA REUNION WITHIN THE NEXT 24 HOURS BEFORE MAKING LANDFALL ALONG THE SOUTH-CENTRAL COAST OF MADAGASCAR AROUND TAU 40. WHILE OVERALL CONDITIONS ARE FORECAST TO REMAIN FAVORABLE THROUGH LANDFALL, MODEST WEAKENING IS FORECAST DUE TO AN EXPECTED EWRC. ASSUMING THE EWRC STARTS SOON, IT SHOULD BE WRAPPED UP AROUND TAU 24, LEAVING BEHIND A LARGER SYSTEM IN GENERAL, WITH A LARGER EYE. CURRENT NCODA AND SATELLITE ANALYSIS REVEALS A WARM POOL, WITH SSTS APPROACHING 29C AND OHC VALUES OVER 40 KJ PER CM2, SITUATED ABOUT 70-100NM OFF THE EAST COAST OF MADAGASCAR. TC 11S IS FORECAST TO TRACK DIRECTLY OVER THIS POOL OF WARMER WATERS AS IT APPROACHES LANDFALL. THE FORECAST THUS CALLS FOR AN INTENSITY OF 110 KNOTS AT TAU 36, WEAKENING TO 90 KNOTS SHORTLY AFTER LANDFALL. IN BETWEEN THESE FORECAST POINTS, THE SYSTEM MAY ACTUALLY REACH A HIGHER INTENSITY AS IT CROSSES THE WARM POOL, SLAMMING INTO MADAGASCAR AS A SIGNIFICANT TC. AS THE SYSTEM CROSSES THE ROUGH TERRAIN OF MADAGASCAR IT WILL WEAKEN DRASTICALLY, LOSING ITS LOW-LEVEL STRUCTURE, BUT MAINTAINING THE MID-LEVEL SIGNATURE. ONCE EXITING THE ISLAND AND EMERGING INTO THE MOZAMBIQUE CHANNEL, TC 11S WILL TURN TO A MORE WESTWARD TO WEST-NORTHWESTWARD TRACK AS THE STEERING MECHANISM SHIFTS TO A BUILDING STR OVER SOUTH AFRICA. ANOTHER ROUND OF INTENSIFICATION, AND POTENTIALLY RAPID INTENSIFICATION IS POSSIBLE IN THE CHANNEL AS THE SYSTEM TAPS INTO A VERY FAVORABLE ENVIRONMENT, WITH SSTS OVER 29C, LOW SHEAR AND STRONG OUTFLOW ALOFT. THE ONLY HINDRANCE WILL BE THE AMOUNT OF TIME IT STAYS OVER WATER BEFORE MAKING LANDFALL ALONG THE CENTRAL COAST OF MOZAMBIQUE.

MODEL DISCUSSION: TRACK GUIDANCE THROUGH LANDFALL IS IN VERY TIGHT AGREEMENT, THOUGH THE NAVGEM AND UKMET ENSEMBLE MEAN TRACKERS HAVE STARTED TO DIVERGE SOUTHWARD. THIS IS A KNOWN BIAS WITH THESE MODELS AND THEY HAVE BEEN DISCARDED FROM THE CONSENSUS. UNSURPRISINGLY, MODELS BEGIN TO DIVERGE AFTER LANDFALL, WITH TWO DISTINCT CAMPS EMERGING BY TAU 72. THE NORTHERN GROUP CONSISTING OF THE US MODELS (GFS, HWRF, COAMPS, AND GEFS) TRACK THE SYSTEM WEST-NORTHWESTWARD AFTER TAU 72. THE SOUTHERN GROUP OF THE EUROPEAN MODELS (ECMWF, UKMET, THEIR ENSEMBLES AND THE NAVGEM) KEEP A RATHER FLAT WESTWARD TRAJECTORY THROUGH TAU 120, WITH ABOUT 120NM BETWEEN THE TWO GROUPS. THE JTWC FORECAST STICKS WITH THE NORTHERN GROUP, THOUGH CONFIDENCE DECREASES TO MEDIUM IN THE LONG-TERM DUE TO THE INCREASED MODEL SPREAD. INTENSITY GUIDANCE IS ALSO IN GOOD AGREEMENT, WITH ALL AVAILABLE GUIDANCE INDICATING WEAKENING, SOME DOWN TO AS LOW AS 100 KNOTS, THROUGH TAU 24, FOLLOWED BY A FLATTENING OF THE TREND THROUGH LANDFALL. THE MODELS CONVERGE AROUND A 40-50 KNOT SYSTEM EMERGING INTO THE CHANNEL AROUND TAU 60, FOLLOWED BY VARIED AMOUNTS OF INTENSIFICATION. THE CTCX KEEPS THE SYSTEM IN THE CHANNEL LONGER AND PEAKS AT 95 KNOTS, WHILE THE HWRF AND COTC PEAK NEAR 65 KNOTS. THE JTWC FORECAST IS CONSISTENT WITH THE COAMPS-TC TRACKER THROUGH THE ENTIRE FORECAST.