22S(GARANCE) CAT 3 US to make landfall over Northern REUNION by 24h//18P(ALFRED) near CAT3// 23S(HONDE) CAT1// 2703utc

FORECAST DISCUSSION: TC 22S HAS BEGUN TO TURN TOWARDS THE EAST WHILE SLOWING DOWN AS THE STEERING INFLUENCE BEGINS TO SHIFT FROM THE NER TO THE NORTH-SOUTH ORIENTED STR TO THE EAST. OVER THE NEXT 12 TO 24 HOURS, THE SYSTEM WILL CONTINUE TO TURN POLEWARD, THOUGH FORWARD TRACK SPEEDS ARE EXPECTED TO REMAIN RELATIVELY SLOW. ONCE FIRMLY ON THE POLEWARD TRAJECTORY, BY AROUND TAU 24, THE SYSTEM WILL START TO ACCELERATE SOUTHWARD. LANDFALL ON THE NORTHERN SHORE OF LA REUNION IS EXPECTED AROUND 0000Z ON THE 28TH. THE SYSTEM CONTINUES TO ACCELERATE POLEWARD AFTER CROSSING OVER LA REUNION, WILL ROUND THE RIDGE AXIS BY TAU 48 AND THEN TURN SOUTHEAST THEN EAST BY THE END OF THE FORECAST PERIOD. BASED ON THE LATEST CIMSS AMV ANALYSIS, THE SYSTEM IS SITUATED JUST EAST OF A DEEP, NORTHEAST TO SOUTHEAST ORIENTED TROUGH WHICH EXTENDS FROM AN UPPER-LEVEL LOW POSITIONED NEAR 27S 51E, OVER LA REUNION AND TO THE NORTHEASTERN TIP OF MADAGASCAR. THIS UPPER-LEVEL ORIENTATION IS PROVIDING THE SYSTEM WITH VERY GOOD OUTFLOW CONDITIONS, WITH A STRENGTHENING POLEWARD OUTFLOW CHANNEL ADDING TO THE ALREADY STRONG EQUATORWARD OUTFLOW. THE FAVORABLE CONDITIONS ARE EXPECTED TO LAST FOR ANOTHER 24 HOURS OR SO, ALLOWING THE SYSTEM TO CONTINUE TO INTENSIFY, TO A PEAK OF AT LEAST 105 KNOTS BY TAU 24. THE SYSTEM WILL BEGIN TO FEEL THE EFFECTS OF INCREASING WIND SHEAR AS IT APPROACHES LANDFALL BUT WILL STILL BE A POWERFUL STORM AS IT MAKES LANDFALL AT LA REUNION. SHEAR IS FORECAST TO RAPIDLY INCREASE BY TAU 36, AND THE SYSTEM WILL BE COMPLETELY SHEARED APART BY ABOUT TAU 48 AS IT ROUNDS THE RIDGE AXIS. SLOW BUT STEADY WEAKENING IS FORECAST FROM TAU 48 THROUGH THE END OF THE FORECAST PERIOD.

MODEL DISCUSSION: DETERMINISTIC TRACK GUIDANCE IS IN TIGHT AGREEMENT, PARTICULARLY THROUGH TAU 48, WITH A CROSS-TRACK SPREAD OF JUST 45NM AT TAU 36. THE GUIDANCE PACKAGE DID SHIFT SLIGHTLY WESTWARD AS A WHOLE OVER THE LAST 12 HOURS, WITH THE CONSENSUS MEAN NOW SITUATED ON THE WESTERN PORTION OF LA REUNION VICE DIRECTLY IN THE CENTER, HOWEVER THE OVERALL SCENARIO HAS NOT CHANGED SIGNIFICANTLY. MODEL DISPERSION INCREASES AFTER TAU 48, OPENING UP TO ABOUT 178NM BY TAU 72 AND MAINTAINING THAT ORIENTATION THROUGH THE REMAINDER OF THE FORECAST PERIOD. THE JTWC FORECAST LIES JUST EAST OF THE CONSENSUS MEAN, CLOSE TO THE ECMWF DETERMINISTIC AND EC-AIFS, BOTH OF WHICH ARE ON THE EASTERN SIDE OF THE GUIDANCE PACKAGE. INTENSITY GUIDANCE IS ALSO IN GOOD AGREEMENT THAT THE SYSTEM WILL CONTINUE TO INTENSIFY FOR THE NEXT 24 HOURS. THE HAFS-A, ALONG WITH THE DTOP RAPID INTENSIFICATION (RI) AID CONTINUE TO TRIGGER, PEAKING THE SYSTEM AT 120-125 KNOTS, WHILE THE COAMPS-TC AND THE CONSENSUS MEAN SHOW A PEAK BETWEEN 100-110 KNOTS. THE JTWC FORECAST SPLITS THE DIFFERENCE BETWEEN THE MORE AGGRESSIVE RI AIDS AND THE CONSENSUS MEAN. HOWEVER, THE COMPACT NATURE OF THE SYSTEM MEANS THAT SIGNIFICANT DEVIATIONS FROM THE INTENSITY FORECAST ARE LIKELY.

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS IMPROVING CONVECTIVE ORGANIZATION AROUND A PRECURSOR EYE FEATURE. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON 262213Z GMI 37 GHZ IMAGERY SHOWING A WELL-DEFINED LOW-LEVEL CIRCULATION CENTER. THE INITIAL INTENSITY OF 95 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON A CONSENSUS OF AVAILABLE SUBJECTIVE DVORAK AND AUTOMATED INTENSITY FIX DATA.

FORECAST DISCUSSION: TROPICAL CYCLONE (TC) 18P WILL CONTINUE TRACKING GENERALLY POLEWARD THROUGH THE ENTIRETY OF THE FORECAST PERIOD UNDER THE ONGOING STEERING INFLUENCE OF THE STR TO THE EAST. A SLIGHT WESTWARD JOG IS POSSIBLE AFTER TAU 36 AS A SUBTROPICAL RIDGE BUILDS TO THE SOUTHWEST AND NUDGES THE SYSTEM, BUT THE INFLUENCE OF THIS RIDGING WILL LIKELY BE MUTED. WHILE THE CURRENT FORECAST CALLS FOR A GENERALLY STEADY INTENSITY TREND OVER THE NEXT 12 TO 24 HOURS, ADDITIONAL INTENSIFICATION IS POSSIBLE AS VERTICAL WIND SHEAR REMAINS LOW AND POLEWARD OUTFLOW ROBUST. HOWEVER, VERTICAL WIND SHEAR IS EXPECTED TO INCREASE AS UPPER-LEVEL FLOW AROUND THE PERIPHERY OF THE SUBTROPICAL RIDGE TO THE EAST IMPACTS THE SYSTEM, EVENTUALLY RESULTING IN A SLOW WEAKENING TREND. BY TAU 120, THE SYSTEM IS EXPECTED TO PASS OVER COOLER WATER (BELOW 26C), BUT THE INTENSITY WILL HOLD STEADY OR DROP VERY SLOWLY AT THAT POINT DUE TO AN INJECTION OF BAROCLINIC SUPPORT. BEYOND THE FORECAST PERIOD, SUBTROPICAL TRANSITION APPEARS LIKELY.

MODEL DISCUSSION: NUMERICAL MODELS ARE IN GOOD AGREEMENT REGARDING THE OVERALL FORECAST SCENARIO AND DERIVED TRACKS ARE FAIRLY TIGHTLY PACKED THROUGH TAU 72, PROVIDING HIGH CONFIDENCE TO THE EARLY PORTION OF THE FORECAST. SPREAD INCREASES THEREAFTER AS DETERMINISTIC CONSENSUS MODELS AND INDIVIDUAL MEMBERS OF GLOBAL ENSEMBLES (GEFS, EC-EPS) INDICATE UNCERTAINTY ASSOCIATED WITH THE INFLUENCE OF A BUILDING RIDGE TO THE SOUTHWEST AFTER TAU 36. SOLUTIONS THAT JOG THE SYSTEM FARTHER WESTWARD ARE ALSO SLOWER TO TURN AND ACCELERATE POLEWARD. TRENDS IN THE FORECAST GUIDANCE SUGGEST THAT ANY WESTWARD JOG AFTER TAU 36 WILL LIKELY BE SMALL AND SHORT LIVED, WHICH THE SUBTROPICAL RIDGE TO THE EAST DOMINATING STEERING. THE CURRENT TRACK FORECAST LIES SLIGHTLY TO THE EAST AND A BIT FASTER THAN THE MULTI-MODEL CONSENSUS WITH MEDIUM CONFIDENCE IN THE EXTENDED RANGE. NEAR-TERM INTENSITY CHANGE IS A BIT UNCERTAIN, WITH HAFS REFLECTING A BUMP TO APPROXIMATELY 105 KTS BUT ALL OTHER SOLUTIONS HOLDING STEADY OR WEAKENING SLOWLY. THE TREND TOWARD SLOW WEAKENING IS SHARED ACROSS MODEL SOLUTIONS AFTER TAU 36. OVERALL, THERE IS MEDIUM CONFIDENCE IN THE INTENSITY FORECAST.

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS INCREASINGLY ORGANIZED DEEP CONVECTIVE BANDING WRAPPING AROUND A SOMEWHAT BROAD LOW-LEVEL CIRCULATION CENTER EVIDENT IN A 261820Z METOP-B ASCAT PASS. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE SUPPORTING METOP-B ASCAT DATA. THE INITIAL INTENSITY OF 60 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON A CONSENSUS OF AGENCY SUBJECTIVE DVORAK AND AUTOMATED ESTIMATES, WITH ADDITIONAL SUPPORT FROM A 261558Z RCM-2 SAR PASS INDICATING WINDS AROUND OR SLIGHTLY HIGHER THAN 60 KNOTS TO THE SOUTHEAST OF THE CIRCULATION CENTER.

FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TROPICAL CYCLONE (TC) 23S WILL CONTINUE TRACKING EAST-SOUTHEASTWARD FOR THE NEXT SEVERAL DAYS UNDER THE CONTINUED STEERING INFLUENCE OF THE NEAR-EQUATORIAL STEERING RIDGE. THE STEERING PATTERN IS EXPECTED TO SHIFT BY TAU 96, WITH THE NER RECEDING AND A SUBTROPICAL RIDGE TO THE EAST BUILDING WESTWARD AND BECOMING THE DOMINANT STEERING MECHANISM, TURNING TC 23 TOWARD A POLEWARD TRACK. ADDITIONALLY, THERE IS SOME POTENTIAL THAT INTERACTION WITH TC 22S TO THE EAST WILL ALTER STORM MOTION IN THE MEDIUM TERM. ENVIRONMENTAL CONDITIONS ARE FAVORABLE FOR ONGOING STEADY TO RAPID INTENSIFICATION OVER THE NEXT 24 HOURS, WITH THE BROAD CIRCULATION CENTER FUNCTIONING AS A LIGHT BRAKE TO THE INTENSIFICATION RATE. AFTER TAU 24, INTERACTION OF THE NORTHERN PORTION OF THE CIRCULATION WITH MADAGASCAR AND DECREASING ALONG-TRACK SEA SURFACE TEMPERATURES ARE EXPECTED TO HALT INTENSIFICATION AND EVENTUALLY RESULT IN SLOW WEAKENING.

MODEL DISCUSSION: NUMERICAL MODELS ARE IN GOOD AGREEMENT REGARDING THE OVERALL TRACK FORECAST SCENARIO THROUGH TAU 72, UNIVERSALLY DEPICTING AN EAST-SOUTHEASTWARD TRACK JUST TO THE SOUTHWEST OF MADAGASCAR UNDER THE CONTINUED INFLUENCE OF THE NER TO THE NORTHEAST. THEREAFTER, GUIDANCE DIVERGES SIGNIFICANTLY, WITH CONSENSUS DETERMINISTIC MODELS AND GLOBAL ENSEMBLE MEMBERS INDICATING THE POTENTIAL FOR A SHARP POLEWARD TURN OR LOOPING MOTION IN EXTENDED PERIOD. THE CURRENT TRACK FORECAST STAYS THE COURSE NEAR BOTH THE PREVIOUS FORECAST AND THE MULTI-MODEL CONSENSUS WITH MEDIUM CONFIDENCE THROUGH TAU 72 AND LOW CONFIDENCE THEREAFTER. NUMERICAL MODEL INTENSITY GUIDANCE SUPPORTS NEAR-TERM INTENSIFICATION FOLLOWED BY SLOW WEAKENING, AND SEVERAL PROBABILISTIC RAPID INTENSIFICATION (RI) AIDS (INCLUDING RIPA AND FRIA) INDICATE THE POTENTIAL FOR RI IN OVER THE NEXT DAY OR SO. CONSIDERING THE MODEL GUIDANCE AND SYNOPTIC SETUP, CONTINUED NEAR-TERM INTENSIFICATION FOLLOWED BY EXTENDED RANGE WEAKENING ARE CERTAIN, BUT THERE IS UNCERTAINTY IN THE TIMING AND RATES OF CHANGE. THERE IS MEDIUM CONFIDENCE IN THE INTENSITY FORECAST ACROSS THE BOARD.