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 : 11/11/20072008 1.A SEVERE TROPICAL STORM 11 (IVAN) 2.A POSITION 2008/02/09 AT 1800 UTC : WITHIN 20 NM RADIUS OF POINT 15.6S / 63.8E (FIFTEEN DECIMAL SIX DEGREES SOUTH AND SIXTY THREE DECIMAL EIGHT DEGREES EAST) 3.A DVORAK ANALYSIS : 3.5/4.0 /W 0.5/24 H 4.A CENTRAL PRESSURE : 980 HPA 5.A MAX AVERAGE WIND SPEED (10 MN) : 55 KT 6.A EXTENSION OF WINDS BY QUADRANTS (KM): 30 KT NE: 150 SE: 100 SO: 150 NO: 150 50 KT NE: 030 SE: 030 SO: 030 NO: 030 7.A FIRST CLOSED ISOBARE (PRESSURE / AVERAGE DIAM): 1005 HPA / 900 KM 8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: DEEP 1.B FORECASTS: 12H: 2008/02/10 06 UTC: 15.6S/64.2E, MAX WIND=055KT, SEVERE TROP. STORM. 24H: 2008/02/10 18 UTC: 15.6S/64.6E, MAX WIND=060KT, SEVERE TROP. STORM. 36H: 2008/02/11 06 UTC: 15.4S/64.8E, MAX WIND=065KT, TROPICAL CYCLONE. 48H: 2008/02/11 18 UTC: 15.3S/64.7E, MAX WIND=060KT, SEVERE TROP. STORM. 60H: 2008/02/12 06 UTC: 15.1S/64.4E, MAX WIND=055KT, SEVERE TROP. STORM. 72H: 2008/02/12 18 UTC: 14.9S/64.0E, MAX WIND=050KT, SEVERE TROP. STORM. 2.B OTHER INFORMATIONS: T=3.5 CI=4.0- IVAN HAS DRIFTED EASTWARDS DURING LAST HOURS. THIS DRIFT SHOULD CONTINUE FOR THE NEXT 24 HOURS IN MORE OR LESS THE SAME DIRECTION AS IVAN IS IN A VERY WEAK STEERING ENVIRONEMENT AND THE SOUTHERN EDGE OF NEAR EQUATORIAL WESTERLIES. ON MONDAY 11, TRACK SHOULD TURN NORTHWESTWARDS AS THE SUBTROPICAL RIDGE BUILDS IN THE SOUTHWEST, BUT STILL AT LOW SPEED AS WESTERLIES THAT WILL STILL PREVAILED AROUND 10S SHOULD HAVE A COMPETITIVE INFLUENCE ON THE STEERING FLOW. SYSTEM IS CURRENTLY EXPERIENCING SOME EASTERLY SHEAR. IF THOSE ENVIRONMENTAL CONDITIONS SHOULD IMPROVE TOMORROW, INTENSIFICATION IS EMPEDED IF THE SYSTEM REMAINS QUASI-STATIONARY QUITE A LONG TIME. PRESENT INTENSITY FORECAST MAY BE GENEROUS MAY BE GENEROUS AND MAY NEED TO BE ADJUSTED DOWNWARDS LATER ... NWP MODELS CONTINUE TO SHOW VERY POOR AGREEMENT ON THIS SYSTEM. PRESENT GUIDANCE IS CLOSE TO THE ECMWF AND ITS ENSEMBLE PREDICTION SYSTEM SOLUTIONS.