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 : 21/4/20072008 1.A MODERATE TROPICAL STORM 4 (CELINA) 2.A POSITION 2007/12/17 AT 1200 UTC : WITHIN 20 NM RADIUS OF POINT 20.0S / 61.2E (TWENTY DECIMAL ZERO DEGREES SOUTH AND SIXTY ONE DECIMAL TWO DEGREES EAST) 3.A DVORAK ANALYSIS : 2.5/3.0 /S 0.0/24 H 4.A CENTRAL PRESSURE : 993 HPA 5.A MAX AVERAGE WIND SPEED (10 MN) : 40 KT 6.A EXTENSION OF WINDS BY QUADRANTS (KM): 30 KT NE: 050 SE: 200 SO: 300 NO: 050 7.A FIRST CLOSED ISOBARE (PRESSURE / AVERAGE DIAM): 1006 HPA / 800 KM 8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: DEEP 1.B FORECASTS: 12H: 2007/12/18 00 UTC: 20.8S/59.6E, MAX WIND=035KT, MODERATE TROP. STORM. 24H: 2007/12/18 12 UTC: 21.8S/58.0E, MAX WIND=030KT, TROP. DEPRESSION. 36H: 2007/12/19 00 UTC: 22.5S/56.8E, MAX WIND=030KT, TROP. DEPRESSION. 48H: 2007/12/19 12 UTC: 22.9S/55.6E, MAX WIND=025KT, TROP. DISTURBANCE. 60H: 2007/12/20 00 UTC: 22.9S/54.5E, MAX WIND=025KT, TROP. DISTURBANCE. 72H: 2007/12/20 12 UTC: 22.6S/53.2E, MAX WIND=025KT, TROP. DISTURBANCE. 2.B OTHER INFORMATIONS: T=2.5 AND CI=3.0- THE SYSTEM KEEPS ON TRACKING RATHER RAPIDLY SOUTHWESTWARDS ALONG THE NORTHWESTERN EDGE OF THE SUBTROPICAL RIDGE CENTRED IN THE SOUTHEAST TOWARDS A TROUGH SHIFTING IN THE SOUTHEAST OF MADAGASCAR. SYSTEM HAS INTENSIFIED DURING LAST NIGHT UNDERGOING A WEAKER VERTICAL WINDSHEAR LINKED TO ITS OWN SPEED WHICH SUBSTRACTS TO THE GENERAL NORTHEASTERLY SHEAR. IT HAS REACHED MODERATE TROPICAL STORM AND HAS BEEN IN CONSEQUENCE NAMED 'CELINA' BY THE MAURTIUS METEOROLOGICAL SERVICES TODAY AT 0430UTC. LAST METEOSAT7 SATELLITE IMAGERY SHOW HOWEVER DISORGANIZATION OF THE DEEP CONVECTIVE ACTIVITY UNDERGOING A DRY ENVIRONMENT, ESPECIALLY AT THE LOWER LEVELAND COOLER SST. CIRRUS ARC BUILDING IN THE NORTH SHOWS AN UPPER LEVEL CONSTRAINT LINKED TO AN ESTABLISHING NORTHWESTERLY VERTICAL WINDSHEAR. 'CELINA' IS EXPECTED TO KEEPS ON TRACKING RAPIDLY SOUTHWESTWARDS WITHIN THE NEXT 36 TO 48 HOURS AND THEN RECURVING WESTWARDS THEN WEST-NORTHWESTWARDS LINKED TO THE REBUILDING SUBTROPICAL HIGH PRESSURES. SYSTEM HAS PROBABLY REACHED ITS MAXIMUM INTENSITY THEN A WEAKENING IS EXPECTED WITH COOLER SST, A STILL DRY ENVIRONMENT AND WEAKER LOWER LEVEL CONVERGENCE (AS THE MID-LATITUDE TROUGH PASSES SOUTHWARD).