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 : 7/4/20082009 1.A TROPICAL DEPRESSION 4 2.A POSITION 2008/12/17 AT 1200 UTC : WITHIN 20 NM RADIUS OF POINT 10.5S / 66.7E (TEN DECIMAL FIVE DEGREES SOUTH AND SIXTY SIX DECIMAL SEVEN DEGREES EAST) MOVEMENT : QUASI-STATIONARY 3.A DVORAK ANALYSIS : 2.5/2.5 /D 0.5/24 H 4.A CENTRAL PRESSURE : 998 HPA 5.A MAX AVERAGE WIND SPEED (10 MN) : 30 KT RADIUS OF MAXIMUM WINDS (RMW) : 30 KM 6.A EXTENSION OF WINDS BY QUADRANTS (KM): 30 KT NE: 040 SE: 080 SO: 080 NO: 040 7.A FIRST CLOSED ISOBARE (PRESSURE / AVERAGE DIAM): 1008 HPA / 1000 KM 8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: MEDIUM 1.B FORECASTS: 12H: 2008/12/18 00 UTC: 11.2S/66.0E, MAX WIND=035KT, MODERATE TROP. STORM. 24H: 2008/12/18 12 UTC: 12.4S/64.8E, MAX WIND=035KT, MODERATE TROP. STORM. 36H: 2008/12/19 00 UTC: 13.2S/63.8E, MAX WIND=030KT, TROP. DEPRESSION. 48H: 2008/12/19 12 UTC: 13.9S/62.5E, MAX WIND=030KT, TROP. DEPRESSION. 60H: 2008/12/20 00 UTC: 14.3S/61.3E, MAX WIND=030KT, TROP. DEPRESSION. 72H: 2008/12/20 12 UTC: 14.8S/60.0E, MAX WIND=030KT, TROP. DEPRESSION. 2.B OTHER INFORMATIONS: T=CI=2.5. VERY LITTLE CHANGE DURING PAST HOURS WITH NO SIGNIFICANT EVOLUTION IN TERMS OF INTENSITY AND A SYSTEM WHICH HAS STALLED ALMOST ON SPOT. THIS SYSTEM EVOLVES WITHIN AN ENVIRONMENT WHICH IS NEUTRAL TO SLIGHTLY FAVOURABLE FOR THE MOMENT. LOCATED BENEATH THE WESTERN PERIPHERY OF THE UPPER RIDGE IT BENEFITS FROM WEAK VERTICAL WINDSHEAR, WHILE THE UPPER OUTFLOW IS RESTRICTED TO A MODERATELY POTENT POLEWARD CHANNEL (AHEAD OF AN UPPER TROUGH TO THE WEST). WHILE THERE IS A CONSENSUS AMONG THE DIFFERENT NUMERICAL MODELS FOR A GENERAL SOUTHWESTWARD MOTION OF THE SYSTEM THEY DISAGREE NOTICEABLY ABOUT THE FUTURE SPEED OF MOVEMENT. THE POTENTIAL FOR FURTHER INTENSIFICATION APPEARS LIMITED ALTHOUGH THERE IS A WINDOW FOR SOME MARGINAL IMPROVEMENT WITHIN THE NEXT 12 TO 24 HOURS BEFORE NORTHERLY TO NORTHWESTERLY WINDS START TO STRENGTHEN AND TO IMPINGE ON THE CLOUD SYSTEM AFFECTING IT THROUGH INCREASING VERTICAL WIND SHEAR.