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 : 3/4/20072008 1.A TROPICAL DISTURBANCE 4 (0420072008) 2.A POSITION 2007/12/13 AT 0000 UTC : WITHIN 40 NM RADIUS OF POINT 13.7S / 69.7E (THIRTEEN DECIMAL SEVEN DEGREES SOUTH AND SIXTY NINE DECIMAL SEVEN DEGREES EAST) 3.A DVORAK ANALYSIS : 2.0/2.0 /D 0.5/24 H 4.A CENTRAL PRESSURE : 1000 HPA 5.A MAX AVERAGE WIND SPEED (10 MN) : 25 KT 6.A EXTENSION OF WINDS BY QUADRANTS (KM): 7.A FIRST CLOSED ISOBARE (PRESSURE / AVERAGE DIAM): 1008 HPA / 800 KM 8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: MEDIUM 1.B FORECASTS: 12H: 2007/12/13 12 UTC: 13.8S/69.5E, MAX WIND=030KT, TROP. DEPRESSION. 24H: 2007/12/14 00 UTC: 13.9S/69.3E, MAX WIND=030KT, TROP. DEPRESSION. 36H: 2007/12/14 12 UTC: 14.1S/69.0E, MAX WIND=035KT, MODERATE TROP. STORM. 48H: 2007/12/15 00 UTC: 14.6S/68.3E, MAX WIND=040KT, MODERATE TROP. STORM. 60H: 2007/12/15 12 UTC: 15.1S/67.4E, MAX WIND=045KT, MODERATE TROP. STORM. 72H: 2007/12/16 00 UTC: 15.7S/66.2E, MAX WIND=050KT, SEVERE TROP. STORM. 2.B OTHER INFORMATIONS: THE LLCC IS STILL BADLY DEFINED AT THIS EARLY STAGE OF DEVELOPMENT. ENVIRONMENTAL CONDITION IS POORLY FAVORABLE. IN LOW LEVEL, EQUATORWARD CONVERGENCE IS GOOD BUT IS WEAKER ON THE TRADEWIND SIDE. A MID-LAT TROUGH THAT SHOULD PASS SOUTH OF THE SYSTEM WITHIN THE NEXT 36 HOURS SHOULD MAINTAIN POOR INFLOW ON THIS SIDE. IN HIGH LEVEL, POLEWARD OUTFLOW IS WELL DEFINED (SEE THE CIRRUS EXPANSION) ASSOCIATED WITH A NORTHWESTWARD SUBTROPICAL JET. THE SYSTEM IS UNDER MODERATE EASTERLY WINDSHEAR, THAT HAS INTENSIFIED DURING THE LAST HOURS. NWP MODELS ARE NOT IN GOOD AGREEMENT, SOME MAKING IT TRACK GLOBALLY SOUTHWESTWARDS (ECMWF, BKNL) WILL OTHER KEEP IT ALMOSTSTATIONNARY, EVEN AT MEDIUM RANGE (ALADIN, ARPEGE-TROPIQUE). THE CMRS FORECAST IS CLOSE TO THE FIRST SCENARIO. THE SYSTEM SHOULD TRACK VERY SLOWLY DURING THE NEXT 36 HOURS, INTENSIFYING SLOWLY TOO, BEFORE LIGHTLY ACCELERATE SOUTHWESTWARDS.