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 : 17/4/20072008 1.A TROPICAL DEPRESSION 4 (0420072008) 2.A POSITION 2007/12/16 AT 1200 UTC : WITHIN 30 NM RADIUS OF POINT 16.9S / 64.8E (SIXTEEN DECIMAL NINE DEGREES SOUTH AND SIXTY FOUR DECIMAL EIGHT DEGREES EAST) 3.A DVORAK ANALYSIS : 2.5/2.5 /S 0.0/24 H 4.A CENTRAL PRESSURE : 997 HPA 5.A MAX AVERAGE WIND SPEED (10 MN) : 30 KT 6.A EXTENSION OF WINDS BY QUADRANTS (KM): 30 KT NE: 050 SE: 150 SO: 200 NO: 090 7.A FIRST CLOSED ISOBARE (PRESSURE / AVERAGE DIAM): 1007 HPA / 1200 KM 8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: MEDIUM 1.B FORECASTS: 12H: 2007/12/17 00 UTC: 17.8S/63.5E, MAX WIND=035KT, MODERATE TROP. STORM. 24H: 2007/12/17 12 UTC: 18.8S/62.1E, MAX WIND=035KT, MODERATE TROP. STORM. 36H: 2007/12/18 00 UTC: 19.3S/60.6E, MAX WIND=030KT, TROP. DEPRESSION. 48H: 2007/12/18 12 UTC: 19.5S/59.4E, MAX WIND=030KT, TROP. DEPRESSION. 60H: 2007/12/19 00 UTC: 19.4S/58.3E, MAX WIND=025KT, TROP. DISTURBANCE. 72H: 2007/12/19 12 UTC: 19.3S/57.0E, MAX WIND=025KT, TROP. DISTURBANCE. 2.B OTHER INFORMATIONS: T=CI=2.5- SYSTEM HAS NOT STRENGHEN SIGNIFICATIVELLY TODAY AND MODERATE NORTHEASTERLY WINDSHEAR (IN THE 15 KT RANGE ACCORDING TO CIMSS DATA) HAS MAINTAINED THE LLCC OUT OF THE MAIN DEEP CONVECTION. AFTER A WESTSOUTHWESTWARDS MOTION AS THE SUBTROPICAL RIDGE TEMPORALLY REBUILT SOUTHWARD, THE SYSTEM HAS NOW A MORE SOUTHWESTWARDS TRACKS TOWARD A MID-LAT TROUGH SOUTHEAST OF MADAGASCAR. AVAILABLE AIDS GIVE A SOUTWESTWARDS TRACK TO THE SYSTEM FOR THE NEXT 24 HOURS FOLLOWED BY A MORE WESTWARDS TO WESTNORTHWESTWARDS MOTION AT A SLOWER SPEED AS THE RIDGE BUILT BACK AFTER THAT. PRESENT GUIDANCE CLOSELY FOLLOW THE CONSENSUS OF DYNAMICAL AIDS. ENVIRONMENTAL CONDITIONS IS RATHER HOSTILE. IN ADDITION OF THE SHEAR, ENVIRONMENT, ESSPECIALLY AT THE LOWER LEVEL, IS DRY AS DEPICTED BY DIFFERENT MICROWAVE PASS TODAY. LOWER CONVERGENCE IS ONLY PRESENT ON THE TRADEWIND SIDE. NEVERTHELESS, AS THE SHEAR IS STILL FORCAST TO ABATE A LITTLE BIT WITHIN THE NEXT 24 HOURS, A SLIGHT INTENSIFICATION TO TROPICAL STORM STATUS IS KEPT. AFTER THAT, AS IN THE PREVIOUS ADVISORY, SOME WEAKENING IS ANTICIPED WITH COOLER SST, A STILL DRY ENVIRONMENT AND WEAKER LOWER LEVEL CONVERGENCE (AS THE MID-LAT TROUGH PASSES SOUTHWARD). WINDS EXTENSION ARE ESTIMATED ACCORDING TO 0435 UTC ASCAT SWATH.