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 : 24/11/20072008 1.A MODERATE TROPICAL STORM 11 (IVAN) 2.A POSITION 2008/02/13 AT 0000 UTC : WITHIN 20 NM RADIUS OF POINT 14.2S / 62.9E (FOURTEEN DECIMAL TWO DEGREES SOUTH AND SIXTY TWO DECIMAL NINE DEGREES EAST) 3.A DVORAK ANALYSIS : 3.0/3.5 /W 0.5/24 H 4.A CENTRAL PRESSURE : 987 HPA 5.A MAX AVERAGE WIND SPEED (10 MN) : 45 KT 6.A EXTENSION OF WINDS BY QUADRANTS (KM): 30 KT NE: 200 SE: 160 SO: 250 NO: 180 7.A FIRST CLOSED ISOBARE (PRESSURE / AVERAGE DIAM): 1005 HPA / 1000 KM 8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: DEEP 1.B FORECASTS: 12H: 2008/02/13 12 UTC: 14.1S/61.7E, MAX WIND=045KT, MODERATE TROP. STORM. 24H: 2008/02/14 00 UTC: 14.1S/60.5E, MAX WIND=050KT, SEVERE TROP. STORM. 36H: 2008/02/14 12 UTC: 14.4S/59.1E, MAX WIND=055KT, SEVERE TROP. STORM. 48H: 2008/02/15 00 UTC: 15.0S/57.6E, MAX WIND=060KT, SEVERE TROP. STORM. 60H: 2008/02/15 12 UTC: 15.5S/56.6E, MAX WIND=070KT, TROPICAL CYCLONE. 72H: 2008/02/16 00 UTC: 16.3S/55.7E, MAX WIND=080KT, TROPICAL CYCLONE. 2.B OTHER INFORMATIONS: T=3.0 AND CI=3.5- DEEP CONVECTION ASSOCIATED TO THE SYSTEM BARELY CONSOLIDATES IN THE SOUTHERN PART; BUT VERTICAL WIND SHEAR OVER THE SYSTREM IS WEAKENING; BEING QUASISTATIONARY OVER THE LAST 36 HOURS, THE OCEANIC HEAT POTENTIAL HAS WEAKENED. IVAN REMAINS UNDER THE INFLUENCE OF TWO COMPETING STEERING FLOWS; SUBTROPICAL HIGH PRESSURES REBUILDING IN THE SOUTH AND EQUATORIAL UPPER LEVEL RIGDE. THE SYSTEM IS NOW TRACKING SLOWLY WESTWARDS. IT IS EXPECTED TO SPEED UP ALONG THE NORTHERN EDGE OF THE SUBTROPICAL RIDGE BECOMING THE PRIMARY STEERING FLOW, AND THEN REGULARLY INTENSIFY WITHIN A MORE FAVORABLE ENVIRONEMENT, UNDER THE UPPER LEVEL RIDGE AND FAR FROM THE AREA OF LOWER OCEAN HEAT CONTENT. BEYOND 24 TO 36 HOURS, IVAN IS FORECASTED TO RECURVE GRADUALLY SOUTHWESTWARDS AS THIS SUBTROPICAL RIDGE WEAKENS.