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 : 10/4/20072008 1.A TROPICAL DEPRESSION 4 (0420072008) 2.A POSITION 2007/12/14 AT 1800 UTC : WITHIN 30 NM RADIUS OF POINT 14.8S / 69.1E (FOURTEEN DECIMAL EIGHT DEGREES SOUTH AND SIXTY NINE DECIMAL ONE DEGREES EAST) 3.A DVORAK ANALYSIS : 2.5/2.5 /D 0.5/24 H 4.A CENTRAL PRESSURE : 999 HPA 5.A MAX AVERAGE WIND SPEED (10 MN) : 30 KT 6.A EXTENSION OF WINDS BY QUADRANTS (KM): 30 KT NE: 130 SE: 290 SO: 280 NO: 175 7.A FIRST CLOSED ISOBARE (PRESSURE / AVERAGE DIAM): 1004 HPA / 800 KM 8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: MEDIUM 1.B FORECASTS: 12H: 2007/12/15 06 UTC: 15.4S/68.4E, MAX WIND=030KT, TROP. DEPRESSION. 24H: 2007/12/15 18 UTC: 15.9S/67.3E, MAX WIND=030KT, TROP. DEPRESSION. 36H: 2007/12/16 06 UTC: 16.4S/65.6E, MAX WIND=040KT, MODERATE TROP. STORM. 48H: 2007/12/16 18 UTC: 16.7S/63.6E, MAX WIND=040KT, MODERATE TROP. STORM. 60H: 2007/12/17 06 UTC: 17.4S/61.9E, MAX WIND=040KT, MODERATE TROP. STORM. 72H: 2007/12/17 18 UTC: 18.5S/60.4E, MAX WIND=040KT, MODERATE TROP. STORM. 2.B OTHER INFORMATIONS: T AND CI=2.5- THE LOW LEVEL CIRCULATION IS PARTIALLY EXPOSED, AS REVEALED ON INFRARED SATELLITE IMAGERY. IT UNDERGOES A NORTHEASTERLY CONSTRAINT WHICH EJECTS ACTIVE DEEP CONVECTION WESTSWARDS. THANKS TO NIGHTLY CYCLE, CONVECTIVE ACTIVITY IS CLOSER TO THE CENTER. SYSTEM HAS BEEN TRACKING SLOWLY SOUTHWESTARDS. CONDITIONS ARE POORLY FAVOURABLE FOR INTENSIFICATION, DUE TO VERTICAL WINDSHEAR, POOR LOW LEVEL TRADEWINDS INFLOW (TROUGH TO THE SOUTH), WEAK UPPER LEVEL DIVERGENCE. THE SYSTEM SHOULD ACCELERATE SOUTHWESTWARDS UNDER THE STEERING INFLUENCE OF A MIDLEVEL SUBTROPICAL RIDGE TO THE SOUTHEAST. IT SHOULD THEN INTENSIFY LIGHTLY (BETTER LOW LEVEL INFLOW, TEMPORARY WEAKENING OF THE VERTICAL WINDSHEAR), WHITOUT REACHING SEVERE TROPICAL STORM STAGE. WINDS EXTENTION IS CALIBRATED THANKS TO 1325UTC QUIKSCAT SWATH.