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 : 6/12/20082009 1.A MODERATE TROPICAL STORM 12 (JADE) 2.A POSITION 2009/04/05 AT 1200 UTC : 13.8S / 51.9E (THIRTEEN DECIMAL EIGHT DEGREES SOUTH AND FIFTY ONE DECIMAL NINE DEGREES EAST) MOVEMENT : WEST-SOUTH-WEST 8 KT 3.A DVORAK ANALYSIS : 3.5/3.5 /D 1.5/24 H 4.A CENTRAL PRESSURE : 990 HPA 5.A MAX AVERAGE WIND SPEED (10 MN) : 45 KT RADIUS OF MAXIMUM WINDS (RMW) : 40 KM 6.A EXTENSION OF WINDS BY QUADRANTS (KM): 30 KT NE: 120 SE: 200 SO: 250 NO: 060 7.A FIRST CLOSED ISOBARE (PRESSURE / AVERAGE DIAM): 1008 HPA / 750 KM 8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: DEEP 1.B FORECASTS: 12H: 2009/04/06 00 UTC: 15.2S/50.8E, MAX WIND=055KT, SEVERE TROP. STORM. 24H: 2009/04/06 12 UTC: 17.1S/49.6E, MAX WIND=030KT, TROP. DEPRESSION. 36H: 2009/04/07 00 UTC: 18.4S/49.2E, MAX WIND=030KT, OVERLAND. 48H: 2009/04/07 12 UTC: 19.7S/48.9E, MAX WIND=030KT, TROP. DEPRESSION. 60H: 2009/04/08 00 UTC: 20.8S/48.7E, MAX WIND=030KT, TROP. DEPRESSION. 72H: 2009/04/08 12 UTC: 21.6S/48.6E, MAX WIND=030KT, TROP. DEPRESSION. 2.B OTHER INFORMATIONS: T AND CI=3.5- CLOUDY PATTERN HAS IMPROVED ON THE VIS AND IR IMAGERY WITHIN THE LAST HOURS, WITH A CONSOLIDATING DEEP CONVECTION. HOWEVER ASCAT SCATTEROMETER WINDS 0525Z ARE STILL RATHER WEAK CLOSE TO THE CENTRE AND SHOW A VERY ASYMMETRIC PATTERN WITH A RING OF STRONG WINDS MAINLY IN THE SOUTHEASTERN SEMI-CIRCLE. ENVIRONMENTAL CONDITIONS ARE FAVOURABLE FOR INTENSIFICATION WITH AN EFFICIENT POLEWARD LOW LEVEL INFLOW ON THE NORTHERN EDGE OF THE SUBTROPICAL HIGH PRESSURES. UPPER LEVEL ENVIRONMENT IS FAVOURABLE WITH A WEAK VERTICAL WINDSHEAR IN THE AREA AND A GOOD DUAL UPPER LEVEL OUTFLOW, OBVIOUS ON THE ANIMATED IMAGERY. HOWEVER WITH THE FORECASTED TRACK, THE SYSTEM SHOULD SKIRT THE EASTERN MALAGASY COAST, THAT SHOULD HAMPER THE INTENSIFICATION. SYSTEM IS UNDER THE STEERING INFLUENCE OF THE NORTHEASTERLY FLOW GENERATED BY THE MID LEVEL RIDGE EXISTING EAST OF THE SYSTEM. AVAILABLE NWP MODELS ARE NOT IN GOOD AGREEMENT WITH THE EXPECTED TRACK. SOME OF THEM FORECAST A DIRECT TRACK TOWARDS THE NORTHEASTERN MALAGASY COASTLINE (LANDFALL WITHIN TAU 12 TO 24) BUT MOST OF THEM FORECAST A SOUTH-SOUTHWESTWARDS TRACK ON AND AFTER TAU 12 ALONG EASTERN MALAGASY COAST. THE SYSTEM INTENSITY WILL STRONGLY DEPEND ON THE TIMING OF THIS EXPECTED SOUTH-SOUTHWESTWARDS TRACK. ON AND AFTER TAU 60, SYSTEM SHOULD UNDERGO A NORTHWESTERLY VERTICAL WINDSHEAR.