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
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RSMC / TROPICAL CYCLONE CENTRE / LA REUNION TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN) 0.A WARNING NUMBER : 7/2/20072008 1.A MODERATE TROPICAL STORM 2 (ARIEL EX-LEE) 2.A POSITION 2007/11/17 AT 0000 UTC : WITHIN 30 NM RADIUS OF POINT 11.5S / 87.3E (ELEVEN DECIMAL FIVE DEGREES SOUTH AND EIGHTY SEVEN DECIMAL THREE DEGREES EAST) 3.A DVORAK ANALYSIS : 3.0/3.0 /W 0.5/24 H 4.A CENTRAL PRESSURE : 990 HPA 5.A MAX AVERAGE WIND SPEED (10 MN) : 40 KT 6.A EXTENSION OF WINDS BY QUADRANTS (KM): 30 KT NE: 160 SE: 270 SO: 240 NO: 090 7.A FIRST CLOSED ISOBARE (PRESSURE / AVERAGE DIAM): 1008 HPA / 500 KM 8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: MEDIUM 1.B FORECASTS: 12H: 2007/11/17 12 UTC: 11.6S/86.8E, MAX WIND=040KT, MODERATE TROP. STORM. 24H: 2007/11/18 00 UTC: 11.9S/86.3E, MAX WIND=040KT, MODERATE TROP. STORM. 36H: 2007/11/18 12 UTC: 12.4S/86.0E, MAX WIND=040KT, MODERATE TROP. STORM. 48H: 2007/11/19 00 UTC: 12.9S/85.5E, MAX WIND=050KT, SEVERE TROP. STORM. 60H: 2007/11/19 12 UTC: 12.7S/84.7E, MAX WIND=050KT, SEVERE TROP. STORM. 72H: 2007/11/20 00 UTC: 12.5S/83.0E, MAX WIND=050KT, SEVERE TROP. STORM. 2.B OTHER INFORMATIONS: T=3.0- AND CI=3.0 ARIEL IS QUASI-STATIONNARY SINCE 1800UTC AND THE CENTER HAS BEEN RELOCATED MORE NORTHERN THANKS TO NEW AVAILABLE MICROWAVE IMAGERY (METOP 1545Z, NOAA18 1928Z AND AQUA 1954Z). SYSTEM KEEPS ON WEAKENING GRADUALLY UNDERGOING A RATHER STRONG NOTHWESTERLY VERTICAL WINDSHEAR. LAST INFRARED METEOSAT7 IMAGERY (FROM 2230Z TO 0000Z) SHOWS A CONVECTIVE ACTIVITY MORE CLOSE TO THE LOW LEVEL CIRCULATION CENTER SYSTEM KEEPS ON WEAKENING WITHIN THE NEXT HOURS AND MOST OF AVAILABLE NWP MODELS FORECAST SLACKENING ACTUAL CONSTRAINTS, SYSTEM COULD ALSO BEGIN A NEW PHASIS OF INTENSIFICATION. THERE IS A STRONG DUBIOUNESS RELATED TO THE FORECAST TRACK AND ALSO INTENSITY DUE TO ANOTHER CYCLOGENESIS VERY CLOSE IN THE VICINITY OF THE CHAGOS. ARIEL IS HOWEVER EXPECTED TO KEEPS ON TRACKING SLOWLY GLOBALLY SOUTHWESTWARDS THEN RECURVE WEST-NORTHWESTWARDS UNDERGOING REBUILDING SUBTROPICAL HIGH PRESURES IN THE SOUTHWEST. THE FORECAST TRACK IS BASED ON CONSENSUS.