Direction Interrégionale de LA REUNION
B.P.4    97491 Ste Clotilde Cedex
Téléphone                02.62.92.11.00
Fax exploitation      02.62.92.11.48
Fax direction           02.62.92.11.47

RSMC / TROPICAL CYCLONE CENTRE / LA REUNION TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN) 0.A WARNING NUMBER : 12/5/20082009 1.A SEVERE TROPICAL STORM 5 (DONGO) 2.A POSITION 2009/01/11 AT 0000 UTC : WITHIN 30 NM RADIUS OF POINT 20.7S / 68.3E (TWENTY DECIMAL SEVEN DEGREES SOUTH AND SIXTY EIGHT DECIMAL THREE DEGREES EAST) MOVEMENT : SOUTH-SOUTH-EAST 11 KT 3.A DVORAK ANALYSIS : 3.5/3.5 /D 0.5/6 H 4.A CENTRAL PRESSURE : 985 HPA 5.A MAX AVERAGE WIND SPEED (10 MN) : 50 KT RADIUS OF MAXIMUM WINDS (RMW) : 30 KM 6.A EXTENSION OF WINDS BY QUADRANTS (KM): 30 KT NE: 330 SE: 270 SO: 270 NO: 130 50 KT NE: 035 SE: 035 SO: 035 NO: 035 7.A FIRST CLOSED ISOBARE (PRESSURE / AVERAGE DIAM): 1008 HPA / 1200 KM 8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: DEEP 1.B FORECASTS: 12H: 2009/01/11 12 UTC: 23.3S/69.2E, MAX WIND=060KT, SEVERE TROP. STORM. 24H: 2009/01/12 00 UTC: 25.9S/70.3E, MAX WIND=050KT, SEVERE TROP. STORM. 36H: 2009/01/12 12 UTC: 29.6S/71.3E, MAX WIND=050KT, BECOMING EXTRATROPICAL. 48H: 2009/01/13 00 UTC: 31.8S/72.6E, MAX WIND=040KT, BECOMING EXTRATROPICAL. 60H: 2009/01/13 12 UTC: 32.9S/74.1E, MAX WIND=040KT, EXTRATROPICAL. 72H: 2009/01/14 00 UTC: 34.6S/77.5E, MAX WIND=040KT, EXTRATROPICAL. 2.B OTHER INFORMATIONS: T=CI=3.5 OVERALL PATTERN HAS IMPROVED DURING THE WHOLE NIGHT WITH AN ONGOING CURVED BAND PATTERN. LATEST ANALYSIS IN EIR IMAGERY SHOWS CONVECTION WRAP OF .90 ON LOG 10 SPIRAL THAT YIELDS TO A DT OF 3.5. ANALYSIS FROM PGTW AND KNES CONFIRM THIS INTENSITY. NO MAJOR CHANGE HAS CAME FROM THE 12Z RUN. AVAILABLE DYNAMICAL GUIDANCE ARE IN GOOD AGREEMENT SHOWING ONLY SOME SLIGHT DISPERSION FOR THE SPEED. PRESENT FORECAST IS BASED ON A GENERAL CONSENSUS BUT CLOSER TO THE LATEST ECMWF TRACK. IT IS JUST SLIGHTLY EASTWARDS OF THE PREVIOUS FORECAST TRACK. SYSTEM IS STILL TRACKING SOUTHSOUTHEASTWARDS (CURRENT MOTION AND SPEED: 155°/11KT) UNDER THE STEERING INFLUENCE OF THE MID-LEVEL RIDGE LOCATED TO THE NORTH EAST OF THE SYSTEM. IT SHOULD REMAIN UNDER THIS STEERING FLOW WITHIN THE NEXT DAYS. ENVIRONMENTAL CONDITIONS ARE STILL FAVOURABLE FOR INTENSIFICATION BUT ARE STILL FORECAST TO DETERIORATE SUNDAY NIGHT WITH A STRONGER NORTHWESTERLY SHEAR AND PROGRESSIVELY COOLER SST. DONGO HAS STILL A WINDOW OF 18 TO 24 HOURS TO REACH ITS MAXIMAL INTENSITY.