WTIO30 FMEE 281306 RSMC / TROPICAL CYCLONE CENTER / LA REUNION TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN) 0.A WARNING NUMBER: 6/5/20172018 1.A INTENSE TROPICAL CYCLONE 5 (CEBILE) 2.A POSITION 2018/01/28 AT 1200 UTC: WITHIN 20 NM RADIUS OF POINT 13.8 S / 83.2 E (THIRTEEN DECIMAL EIGHT DEGREES SOUTH AND EIGHTY THREE DECIMAL TWO DEGREES EAST) MOVEMENT : SOUTH-WEST 10 KT 3.A DVORAK ANALYSIS: 5.5/5.5/D 3.0/24 H 4.A CENTRAL PRESSURE: 950 HPA 5.A MAX AVERAGE WIND SPEED (10 MN): 95 KT RADIUS OF MAXIMUM WINDS (RMW) :11 KM 6.A EXTENSION OF WIND BY QUADRANTS (KM): 28 KT NE: 280 SE: 190 SW: 340 NW: 180 34 KT NE: 80 SE: 80 SW: 90 NW: 130 48 KT NE: 50 SE: 50 SW: 50 NW: 50 64 KT NE: 30 SE: 30 SW: 30 NW: 30 7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1005 HPA / 700 KM 8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : DEEP 1.B FORECASTS: 12H: 2018/01/29 00 UTC: 14.8 S / 82.3 E, MAX WIND=110 KT, INTENSE TROPICAL CYCLONE 24H: 2018/01/29 12 UTC: 15.7 S / 81.5 E, MAX WIND=110 KT, INTENSE TROPICAL CYCLONE 36H: 2018/01/30 00 UTC: 16.1 S / 80.9 E, MAX WIND=100 KT, INTENSE TROPICAL CYCLONE 48H: 2018/01/30 12 UTC: 16.3 S / 80.4 E, MAX WIND=090 KT, INTENSE TROPICAL CYCLONE 60H: 2018/01/31 00 UTC: 16.4 S / 79.7 E, MAX WIND=085 KT, TROPICAL CYCLONE 72H: 2018/01/31 12 UTC: 16.6 S / 79.0 E, MAX WIND=080 KT, TROPICAL CYCLONE 2.B LONGER-RANGE OUTLOOK : 96H: 2018/02/01 12 UTC: 17.3 S / 78.7 E, MAX WIND=070 KT, TROPICAL CYCLONE 120H: 2018/02/02 12 UTC: 18.4 S / 79.7 E, MAX WIND=050 KT, SEVERE TROPICAL STORM 2.C ADDITIONAL INFORMATION: T=CI=5.5+ CEBILE UNDERWENT EXTREMELY RAPID INTENSIFICATION OVER THE LAST 24 HOURS (+65 KT !). THIS AFTERNOON, THE EYE HAS CONTINUED TO BECOME BETTER DEFINED, AS IT HAS CONTRACTING AND WARMING. CEBILE IS A SMALL INNER CORE SYSTEM AND THAT FEATURE FAVOR RAPID INTENSITY CHANGE. THE CURRENT ASSESSMENT OF THE INTENSITY IS BASED ON THE RSMC DVORAK ANALYSIS WHERE 6HR CONSTRAINT ON FT HAS BEEN APPLIED (CONSTRAINT ON FT VARIATION IN 12, 18 AND 24 HOURS ARE BROKEN). THE INTENSITY AT 95 KT MAY BE SOMEWHAT CONSERVATIVE GIVEN THE RATHER SIGNIFICANT SATELLITE VIEWING ANGLE WITH MSG-1. RAW ADT IS BETWEEN 6.1 AND 6.3 SINCE THE TIME THE EYE FEATURE HAS BEEN DETECTED (0845Z). THE NON-CORRECTED AMSU ESTIMATES AT 89 KT (1 MIN WINDS) AT 1012Z IS LIKELY TOO LOW GIVEN THE SMALL INNER-CORE OF CEBILE SEEN ON AMSU PRODUCT. CEBILE TRACKS NOW SOUTH-WESTWARD ON THE NORTH-WESTERN EDGE OF THE SUBTROPICAL RIDGE. THEN THE REINFORCEMENT AND THE NORTHWARD EXTENSION OF THE RIDGE IN ITS SOUTH-WESTERN PART WILL SLOW THE MOVEMENT OF CEBILE AND BEND THE FORWARD MOTION TEMPORARILY TOWARDS THE WEST. IN THE MIDDLE OF NEXT WEEK, THE RIDGE WEAKENS TO ITS SOUTH-EAST ALONG WITH A BUILDING NEAR EQUATORIAL RIDGE TO ITS NORTH-EAST ALLOWING THE SYSTEM TO TAKE A TURN SOUTHEASTWARD. HOWEVER THERE IS ALWAYS A LARGE UNCERTAINTY ABOUT THE TRACK BEYOND MONDAY MAINLY DU TO THE WIDE VARIABILITY IN THE SPEED OF MOVEMENT AMONG THE NUMERICAL GUIDANCE. SO THERE IS STILL SOME SIGNIFICANT UNCERTAINTY ON WHERE THE SYSTEM IS EXPECTED TO TURN SOUTH-EASTWARD. THE CURRENT FORECAST IS A BLEND OF THE LATEST GUIDANCE WITH ONLY MINOR CHANGE COMPARED TO THE PREVIOUS CYCLE. ALONG THIS TRACK, THE SYSTEM SHOULD FIRST MAINTAIN INTENSIFICATION AS THE UPPER LEVEL CONSTRAINT IS WEAK. HOWEVER, CEBILE WILL TRANSIT ON AREAS WHERE THE OCEANIC POTENTIAL IS LESS. MOREOVER, FROM TUESDAY THE SURROUNDING MID-LEVEL ENVIRONMENT IS EXPECTED TO BECOME VERY DRY SPECIALLY OVER THE WESTERN AND NORTHERN SEMI-CIRCLE. CEBILE MAY START BY THAT TIME A SLOW WEAKENING TREND THAT MAY INCREASE LATER IN THE FORECAST PERIOD WHERE WESTERLY SHEAR INCREASE. INTERNAL DYNAMICS (EYE WALL REPLACEMENT CYCLE) MAY ALSO MODULATE THE INTENSITY BUT THIS MECHANISM HAS VERY LOW PREDICTABILITY (VERY SHORT RANGE)=