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 : 25/11/20072008 1.A MODERATE TROPICAL STORM 11 (IVAN) 2.A POSITION 2008/02/13 AT 0600 UTC : WITHIN 30 NM RADIUS OF POINT 13.8S / 62.2E (THIRTEEN DECIMAL EIGHT DEGREES SOUTH AND SIXTY TWO DECIMAL TWO DEGREES EAST) 3.A DVORAK ANALYSIS : 2.5/3.0 /W 1.5/24 H 4.A CENTRAL PRESSURE : 990 HPA 5.A MAX AVERAGE WIND SPEED (10 MN) : 40 KT 6.A EXTENSION OF WINDS BY QUADRANTS (KM): 30 KT NE: 200 SE: 160 SO: 250 NO: 200 7.A FIRST CLOSED ISOBARE (PRESSURE / AVERAGE DIAM): 1005 HPA / 1100 KM 8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: DEEP 1.B FORECASTS: 12H: 2008/02/13 18 UTC: 13.9S/60.7E, MAX WIND=040KT, MODERATE TROP. STORM. 24H: 2008/02/14 06 UTC: 14.0S/59.1E, MAX WIND=050KT, SEVERE TROP. STORM. 36H: 2008/02/14 18 UTC: 14.4S/58.0E, MAX WIND=060KT, SEVERE TROP. STORM. 48H: 2008/02/15 06 UTC: 15.1S/57.0E, MAX WIND=070KT, TROPICAL CYCLONE. 60H: 2008/02/15 18 UTC: 16.0S/56.2E, MAX WIND=080KT, TROPICAL CYCLONE. 72H: 2008/02/16 06 UTC: 17.3S/55.2E, MAX WIND=085KT, TROPICAL CYCLONE. 2.B OTHER INFORMATIONS: T=2.5 AND CI=3.0 IVAN HAS TRACKED WEST-NORTHWESTWARDS AT 8 KNOTS OVER THE LAST 6 HOURS. AS IT TRACK OVER COOLER SST (INDUCE BY HIS LOW MOTION OVER THE LAST DAYS), DEEP CONVECTION ASSOCIATED TO THE SYSTEM HAS WEAKEN OVER THE SYSTEM LAST NIGHT. CI HAS BEEN ADJUSTED CONSEQUENTLY. THE SYSTEM SHOULD TRACK GENERALLY WESTWARDS ALONG THE NORTHERN EDGE OF THE SUBTROPICAL RIDGE BECOMING THE PRIMARY STEERING FLOW. IT SHOULD REGULARLY INTENSIFY WITHIN A MORE FAVORABLE ENVIRONEMENT, UNDER THE UPPER LEVEL RIDGE (LESS EASTERLY SHEAR) 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. THERE IS CURRENTLY SOME SPREAD ON HOW STRONG IVAN WILL CURVE SOUTHWESTWARDS (CF. STRIKE PROBABILITIES OF THE ECMWF). PRESENT GUIDANCE IS CLOSE TO THE ECMWF, CONW AND GFS SOLUTIONS.