TC 11S(FREDDY)set to make landfall near Mananjary/MADAGASCAR shortly after 24h as a strong CAT3 US//Invest 99W//Invest 93S// 2015utc

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

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: TC FREDDY IS SHOWING SIGNS OF WEAKENING AS IT TRANSITS NORTH OF MAURITIUS AND LA REUNION. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A FAIRLY SYMMETRICAL SYSTEM WITH EVIDENCE OF SPIRAL BANDING IN THE NORTHERN AND SOUTHERN PERIPHERIES. ANALYSIS OF THE 201200Z IR-BD LOOP INDICATES DETERIORATION OF THE EYEWALL IN THE SOUTHWEST QUADRANT, AND INSPECTION OF THE CIMMS 6-HOUR CLOUD TOP TEMPERATURE TRENDS REVEAL WARMING CLOUD TOPS IN THE SOUTHEAST QUADRANT. THE 201300Z METAR FROM SIR SEEWOOSAGUR RAMGOOLAM INTERNATIONAL AIRPORT, MAURITIUS REPORTS WINDS FROM THE EAST-NORTHEAST AT 30 KNOTS WITH GUSTS OF 42 KNOTS. ENVIRONMENTAL ANALYSIS INDICATES TC 11S TO BE IN FAVORABLE CONDITIONS FOR CONTINUAL TROPICAL ACTIVITY. THESE CONDITIONS ARE CHARACTERIZED BY CONSISTENT WESTERLY OUTFLOW ALOFT, LOW (5-10 KTS) VERTICAL WIND SHEAR (VWS), A VERY STRONG 850 MB VORTICITY SIGNATURE, AND WARM (27-28 C) SEA SURFACE TEMPERATURES (SST). THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE AFOREMENTIONED MSI AND THE MAURITIUS RADAR LOOP. THE INITIAL INTENSITY OF 120 KTS IS ASSESSED WITH MEDIUM CONFIDENCE SET BASED OF THE BLEND OF MULTI-AGENCY AND AUTOMATED DVORAK ESTIMATES.

FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TC FREDDY CONTINUES ITS WEST-SOUTHWESTWARD TRACK AS IT TRANSITS THE NORTHEASTERN PERIPHERY OF THE STR TO THE SOUTH. COPIOUS AMOUNTS OF DRY AIR WILL CONTINUE TO SURROUND THE SYSTEM, HOWEVER, TC FREDDY WILL STAY COCOONED IN ITS OWN MOISTURE POCKET DURING ITS FORECAST TRACK. THE SYSTEM WILL CONTINUE ITS WEST-SOUTHWESTWARD TRAJECTORY AND GRADUALLY DECREASE IN INTENSITY TO 105 KNOTS AS IT MAKES ITS APPROACH TO THE EAST COAST OF MADAGASCAR SHORTLY AFTER TAU 24. TC 11S IS FORECAST TO FURTHER DECREASE IN INTENSITY TO 75 KNOTS BY TAU 36, AND 50 KNOTS BY TAU 48, AS IT TRANSITS ACROSS THE MOUNTAINOUS TERRAIN OF SOUTHERN MADAGASCAR. BY TAU 72, THE SYSTEM WILL BE IN ANOTHER FAVORABLE ENVIRONMENT OVER THE MOZAMBIQUE CHANNEL AND RE-INTENSIFY TO 65 KNOTS AS A RESULT. IT SHOULD BE NOTED THAT THE HIGH RESOLUTION COMAPS-TC INTENSITY GUIDANCE INDICATES RAPID INTENSIFICATION AS TC FREDDY TRANSITS OVER THE MOZAMBIQUE CHANNEL DURING THIS TIME. BY TAU 96, TC 11S WILL DECREASE TO 40 KNOTS AFTER IT MAKES LANDFALL SOUTH OF BEIRA, MOZAMBIQUE. BY TAU 120, TC FREDDY WILL DISSIPATE AS A 25 KNOT SYSTEM NEAR THE ZIMBABWE-SOUTH AFRICA BORDER.

MODEL DISCUSSION: THE JTWC TRACK CONSENSUS MEMBERS ARE IN AGREEMENT WITH A CONTINUAL WEST-SOUTHWEST TRACK, THEN SHIFTING TO A MORE WESTWARD TRACK AFTER CROSSING OVER MADAGASCAR. THE UK AND NAVGEM TRACKERS ARE THE OUTLIERS SHOWING MORE OF A SOUTHWESTWARD TRACK THROUGHOUT THE FORECAST PERIOD. BECAUSE THIS THIS, THE JTWC FORECAST TRACK TO SET TO THE RIGHT OF THE CONSENSUS TRACK WITH MEDIUM CONFIDENCE. THE JTWC INTENSITY CONSENSUS MEMBERS ARE ALSO IN GOOD AGREEMENT WITH THE EXCEPTION OF GFS WHICH DECREASES THE INTENSITY WELL BEYOND THE OTHER CONSENSUS MEMBERS. AS A RESULT, THE JTWC INTENSITY FORECAST IS SET WITH MEDIUM CONFIDENCE.

THE AREA OF CONVECTION (INVEST 99W) PREVIOUSLY LOCATED NEAR 16.0N 123.6E IS NOW LOCATED NEAR 17.2N 124.3E, APPROXIMATELY 246 NM NORTHEAST OF MANILA, PHILIPPINES. ANIMATED ENHANCED INFRARED IMAGERY (EIR) AND A 200854Z SSMIS 91GHZ MICROWAVE PASS SHOWS AN AREA OF DEEP CONVECTION DISPLACED TO THE NORTHEAST OF A LOW LEVEL CIRCULATION CENTER (LLCC). ENVIRONMENTAL ANALYSIS REVEALS THAT 99W IS IN A MARGINALLY FAVORABLE REGION FOR DEVELOPMENT AS A RESULT OF MODERATE TO HIGH (15-20KT) VWS, OFFSET BY GOOD POLEWARD OUTFLOW AND WARM (26-27C) SSTS. THE VWS IS EXPECTED TO INCREASE SIGNIFICANTLY TO 30-40 KNOTS BETWEEN NOW AND TAU 24, THEN OVER 40 KNOTS BY TAU 36. IN ADDITION, THE MID-LEVEL MOISTURE IS EXPECTED TO GRADUALLY DECREASE OVER THE NEXT 48 HOURS AS DRY AIR FORM THE NORTHEAST COLD SURGE WILL INFRINGE INTO THE CIRCULATION. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO 20 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1004 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS DOWNGRADED TO LOW.