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 : 1/12/20082009 1.A ZONE OF DISTURBED WEATHER 12 2.A POSITION 2009/04/04 AT 0600 UTC : WITHIN 30 NM RADIUS OF POINT 11.1S / 56.6E (ELEVEN DECIMAL ONE DEGREES SOUTH AND FIFTY SIX DECIMAL SIX DEGREES EAST) MOVEMENT : QUASI-STATIONARY 3.A DVORAK ANALYSIS : 1.5/1.5 /D 0.5/24 H 4.A CENTRAL PRESSURE : 1004 HPA 5.A MAX AVERAGE WIND SPEED (10 MN) : 20 KT RADIUS OF MAXIMUM WINDS (RMW) : NIL 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: 2009/04/04 18 UTC: 12.1S/55.7E, MAX WIND=025KT, TROP. DISTURBANCE. 24H: 2009/04/05 06 UTC: 13.1S/54.9E, MAX WIND=035KT, MODERATE TROP. STORM. 36H: 2009/04/05 18 UTC: 14.2S/54.1E, MAX WIND=040KT, MODERATE TROP. STORM. 48H: 2009/04/06 06 UTC: 15.4S/53.5E, MAX WIND=050KT, SEVERE TROP. STORM. 60H: 2009/04/06 18 UTC: 17.2S/53.0E, MAX WIND=060KT, SEVERE TROP. STORM. 72H: 2009/04/07 06 UTC: 18.8S/53.1E, MAX WIND=060KT, SEVERE TROP. STORM. 2.B OTHER INFORMATIONS: T AND CI=1.5 DEEP CONVECTIVE ACTIVITY EXISTS SINCE YESTERDAY EVENING AND HAS CLEARLY IMPROVED. ENVIRONMENTAL CONDITIONS ARE FAVOURABLE FOR INTENSIFICATION WITH A EFFICIENT POLEWARD LOW LEVEL INFLOW ON THE NORTHERN EDGE OF THE SUBTROPICAL HIGH PRESSURES REBUILDING IN THE SOUTHWEST. EVEN IT DOESN'T EXIST POLEWARDS, MONSOON FLOW IS EXPECTED TO BEGIN ON ESTABLISHING WEST OF 55E ON AND AFTER MONDAY. UPPER LEVEL ENVIRONMENT IS FAVOURABLE WITH A WEAK VERTICAL WINDSHEAR IN THE AREA AND A GOOD POLEWARD UPPER LEVEL OUTFLOW (CF CIRRUS ARC EXISTING 350NM IN THE SOTHWEST). ANOTHER UPPER LEVEL OUTLOW (EQUATORWARD) IS EXPECTED TO BUILD ON SUNDAY BUT SHOULD NOT BE SO EFFICIENT AS THE POLEWARD ONE. SYSTEM IS EXPECTED TO BE DRIVED BY THE NORTHERLY STEERING FLOW GENERATED BY THE MERIDIAN MID LEVEL RIDGE EXISTING EAST OF THE SYSTEM, STRETCHING ALONG 63E AXIS. ON AND AFTER TAU 60, SYSTEM SHOULD BE CONSTRAINTED BY NORTHWESTARLY VERTICAL WINDSHEAR.