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 : 3/2/20072008 1.A SEVERE TROPICAL STORM 2 (ARIEL EX-LEE) 2.A POSITION 2007/11/16 AT 0000 UTC : WITHIN 40 NM RADIUS OF POINT 11.7S / 88.8E (ELEVEN DECIMAL SEVEN DEGREES SOUTH AND EIGHTY EIGHT DECIMAL EIGHT DEGREES EAST) 3.A DVORAK ANALYSIS : 3.5/3.5 /S 4.A CENTRAL PRESSURE : 984 HPA 5.A MAX AVERAGE WIND SPEED (10 MN) : 50 KT 6.A EXTENSION OF WINDS BY QUADRANTS (KM): 30 KT NE: 110 SE: 250 SO: 250 NO: 100 50 KT NE: 025 SE: 025 SO: 025 NO: 025 7.A FIRST CLOSED ISOBARE (PRESSURE / AVERAGE DIAM): 1008 HPA / 600 KM 8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: MEDIUM 1.B FORECASTS: 12H: 2007/11/16 12 UTC: 11.9S/87.6E, MAX WIND=050KT, SEVERE TROP. STORM. 24H: 2007/11/17 00 UTC: 12.1S/86.5E, MAX WIND=050KT, SEVERE TROP. STORM. 36H: 2007/11/17 12 UTC: 12.3S/85.5E, MAX WIND=050KT, SEVERE TROP. STORM. 48H: 2007/11/18 00 UTC: 12.6S/85.2E, MAX WIND=050KT, SEVERE TROP. STORM. 60H: 2007/11/18 12 UTC: 13.1S/85.1E, MAX WIND=050KT, SEVERE TROP. STORM. 72H: 2007/11/19 00 UTC: 13.5S/85.0E, MAX WIND=050KT, SEVERE TROP. STORM. 2.B OTHER INFORMATIONS: T AND CI = 3.5. THE LOCATION OF THE CENTER HAS TO BE IMPROVED WITH FURTHER OBJECTIVE DATA (MICRO-WAVE PASSES). SYSTEM IS SHOWING CLEAR SIGNS OF NORTHWESTERLY VERTICAL WINDSHEAR DUE TO HIGH LEVEL WINDS SOUTH OF 15S (TILT BETWEEN 37GHZ AND 85 GHZ CHANNELS OVER SSMIS DATA, WIDE CIRRUS ARCUS OVER THE NORTHWESTERN SEMI-CIRCLE) METEOSAT7 SATELLITE IMAGERIES SHOW HOWEVER A STILL VERY COLD, DENSE AND SPREAD DEEP CONVECTION. POTENTIAL FOR INTENSIFICATION REMAINS LIMITED DUE TO LESS FAVOURABLE ENVIRONMENTAL CONDITIONS WITH A NARROW WINDOW OF WEAK VERTICAL WINDSHEAR. ARIEL SHOULD BE STEERED WESTWARDS BY THE SUBTROPICAL RIDGE SOUTHWARDS DURING THE NEXT 36 HOURS, BEFORE SLOWING DOWN DUE TO A WEAKNESS IN THE RIDGE.