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 : 4/4/20072008 1.A TROPICAL DISTURBANCE 4 (0420072008) 2.A POSITION 2007/12/13 AT 0600 UTC : WITHIN 30 NM RADIUS OF POINT 14.6S / 68.6E (FOURTEEN DECIMAL SIX DEGREES SOUTH AND SIXTY EIGHT DECIMAL SIX DEGREES EAST) 3.A DVORAK ANALYSIS : 2.0/2.0 /S 0.0/12 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 18 UTC: 14.8S/68.4E, MAX WIND=030KT, TROP. DEPRESSION. 24H: 2007/12/14 06 UTC: 15.0S/68.2E, MAX WIND=030KT, TROP. DEPRESSION. 36H: 2007/12/14 18 UTC: 15.2S/67.9E, MAX WIND=035KT, MODERATE TROP. STORM. 48H: 2007/12/15 06 UTC: 15.6S/67.4E, MAX WIND=040KT, MODERATE TROP. STORM. 60H: 2007/12/15 18 UTC: 16.1S/66.3E, MAX WIND=045KT, MODERATE TROP. STORM. 72H: 2007/12/16 06 UTC: 16.3S/64.8E, MAX WIND=050KT, SEVERE TROP. STORM. 2.B OTHER INFORMATIONS: T AND CI=2.0 THE LLCC IS STILL BADLY DEFINED AT THIS EARLY STAGE OF DEVELOPMENT. LAST NIGHT QUIKSCAT SWATH AND 0028Z MICROWAVE NOAA15 SHOWS AN ELONGATED CIRCULATION FROM THE MAIN LLCC TOWARDS THE NORTHEAST. ENVIRONMENTAL CONDITIONS IS POORLY FAVORABLE. IN LOW LEVELS, 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 ASSOCIATED WITH A NORTHWESTWARDS SUBTROPICAL JET. EQUATORWARD, EAST-NORTHEASTERLY VERTICAL WHINDSHEAR SEEMS TO DECREASE SINCE THE RECENT PAST HOURS (SEE THE CIRRUS EXPANSION NORTHWARDS) . NWP MODELS ARE IN AGREEMENT TO LET THE SYSTEM IN THE SAME AREA DURING THE NEXT 48 HOURS UNDERGOING OPPOSITE STEERING FLOWS IN THE MID-LEVELS (WESTERLIES IN THE NORTH, SOUTHEASTERLIES IN THE EAST AND NORTHWESTERLIES IN THE SOUTH). THE SYSTEM SHOULD TRACK SLOWLY GLOBALLY SOUTHWESTWARDS DURING THE NEXT 48 HOURS AS IT LIGHTLY INTENSIFIES AND THEN IS EXPECTED TO RECURVE MORE WESTWARDS ACCELERATING.