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 : 10/5/20052006 1.A TROPICAL CYCLONE 5 (ALVIN EX-BERTIE) 2.A POSITION 2005/11/25 AT 0000 UTC : WITHIN 30 NM RADIUS OF POINT 14.7S / 89.2E (FOURTEEN DECIMAL SEVEN DEGREES SOUTH AND EIGHTY NINE DECIMAL TWO DEGREES EAST) 3.A DVORAK ANALYSIS : 4.0/5.0 /W 1.0/12 H 4.A CENTRAL PRESSURE : 955 HPA 5.A MAX AVERAGE WIND SPEED (10 MN) : 80 KT 6.A EXTENSION OF WINDS BY QUADRANTS (KM): 30 KT NE: 180 SE: 250 SO: 200 NO: 150 50 KT NE: 050 SE: 080 SO: 080 NO: 050 7.A FIRST CLOSED ISOBARE (PRESSURE / AVERAGE DIAM): 1008 HPA / 800 KM 8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: DEEP 1.B FORECASTS: 12H: 2005/11/25 12 UTC: 14.8S/88.8E, MAX WIND=060KT . 24H: 2005/11/26 00 UTC: 14.9S/87.7E, MAX WIND=055KT . 36H: 2005/11/26 12 UTC: 15.0S/86.5E, MAX WIND=050KT . 48H: 2005/11/27 00 UTC: 14.8S/84.9E, MAX WIND=045KT . 60H: 2005/11/27 12 UTC: 14.8S/83.4E, MAX WIND=040KT . 72H: 2005/11/28 00 UTC: 15.1S/81.7E, MAX WIND=035KT . 2.B OTHER INFORMATIONS: T=4.0+, CI=5.0+ THE TROPICAL CYCLONE ALVIN CONTINUES TO WEAKEN IN A LESS AND LESS FAVORABLE ENVIRONMENT. SINCE THE EYE HAS DISSAPEARED (NEAR 1500UTC ON INDOEX INFRARED SATELLITE IMAGERY), ALVIN IS CONSTRAINTED BY A WESTERLY VERTICAL WINDSHEAR (20KT ACCORDING TO CIMSS) AND DEEPEST CONVECTION IS MAINLY LOCATED IN THE SOUTHEASTERN QUADRANT. IT IS EXPECTED TO CONTINUE TRACKING WESTWARDS DURING THE NEXT HOURS, ON THE NORTHERN EDGE OF THE SUBTROPICAL HIGH PRESSURES. THE SYSTEM SHOULD THEN SIGNIFICANTLY WEAKEN AS THE WINDSHEAR INCREASE AND THE AIR BECOMES DRYER (VAPOR SSMI AND WV IMAGERY) OVER COOLER SEA.