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 : 29/11/20072008 1.A SEVERE TROPICAL STORM 11 (IVAN) 2.A POSITION 2008/02/14 AT 0600 UTC : 13.6S / 59.5E (THIRTEEN DECIMAL SIX DEGREES SOUTH AND FIFTY NINE DECIMAL FIVE DEGREES EAST) 3.A DVORAK ANALYSIS : 3.5/3.5 /D 1.0/24 H 4.A CENTRAL PRESSURE : 983 HPA 5.A MAX AVERAGE WIND SPEED (10 MN) : 50 KT 6.A EXTENSION OF WINDS BY QUADRANTS (KM): 30 KT NE: 300 SE: 230 SO: 300 NO: 250 50 KT NE: 050 SE: 050 SO: 050 NO: 050 7.A FIRST CLOSED ISOBARE (PRESSURE / AVERAGE DIAM): 1007 HPA / 1100 KM 8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: DEEP 1.B FORECASTS: 12H: 2008/02/14 18 UTC: 14.0S/57.7E, MAX WIND=055KT, SEVERE TROP. STORM. 24H: 2008/02/15 06 UTC: 14.6S/56.1E, MAX WIND=060KT, SEVERE TROP. STORM. 36H: 2008/02/15 18 UTC: 15.0S/54.9E, MAX WIND=065KT, SEVERE TROP. STORM. 48H: 2008/02/16 06 UTC: 15.4S/54.2E, MAX WIND=070KT, TROPICAL CYCLONE. 60H: 2008/02/16 18 UTC: 15.8S/53.7E, MAX WIND=080KT, TROPICAL CYCLONE. 72H: 2008/02/17 06 UTC: 16.7S/53.0E, MAX WIND=090KT, INTENSE TROP. CYCL.. 2.B OTHER INFORMATIONS: T=CI=3.5 LATEST QUIKSCAT DATA AT 0210Z SHOWS INTENSIFICATION OF WINDS, THEN LIGHT INTESIFICATION OF THE SYSTEM. NEVERTHELESS, LAST AVAILABLE MICROWAVE IMAGERY, SSMI 14/0214Z SHOWS THAT DEEP CONVECTION RE-ORGANIZES VERY SLOWLY AND THE CENTER OF THE MIDLEVEL CIRCULATION IS LOCATED LIGHTLY NORTHWEST OF THE LLCC (EASTSOUTHEASTERLY VERTICAL SHEAR). THE SYSTEM SHOULD GENERALLY CONTINUE TO TRACK WESTWARDS ALONG THE NORTHERN EDGE OF THE SUBTROPICAL RIDGE BECOME THE PRIMARY STEERING FLOW. IT SHOULD THEN KEEP ON REGULARLY INTENSIFYING - QUICKER BEYOND TAU 36H -WITHIN A MORE FAVORABLE ENVIRONMENT, UNDER THE UPPER LEVEL RIDGE (WEAKER EASTERLY SHEAR) AND WEST OF 60E, FAR FROM THE AREA OF LOWER OCEAN HEAT CONTENT. ON FRIDAY 15, IVAN IS FORECASTED TO GRADUALLY HAVE A POLEWARD TURN AS THE SUBTROPICAL RIDGE WEAKENS AND A MID-TROPOSPHERIC RIDGE IS BUILDING NORTH-EAST OF THE SYSTEM. SPEED MOVEMENT SHOULD THEN DECREASE. AVAILABLE DYNAMIC AIDS ARE IN BETTER AGREEMENT AND THIS FORECAST IS CLOSE TO THE ECMWF AND A CONSENSUS OF AMERICAN MODELS.