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
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RSMC / TROPICAL CYCLONE CENTRE / LA REUNION TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN) 0.A WARNING NUMBER : 22/4/20072008 1.A MODERATE TROPICAL STORM 4 (CELINA) 2.A POSITION 2007/12/17 AT 1800 UTC : WITHIN 30 NM RADIUS OF POINT 20.3S / 60.7E (TWENTY DECIMAL THREE DEGREES SOUTH AND SIXTY DECIMAL SEVEN DEGREES EAST) 3.A DVORAK ANALYSIS : 2.5/3.0 /W 0.5/12 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 06 UTC: 21.1S/59.1E, MAX WIND=035KT, MODERATE TROP. STORM. 24H: 2007/12/18 18 UTC: 21.8S/57.7E, MAX WIND=030KT, TROP. DEPRESSION. 36H: 2007/12/19 06 UTC: 22.0S/56.3E, MAX WIND=030KT, TROP. DEPRESSION. 48H: 2007/12/19 18 UTC: 21.9S/55.2E, MAX WIND=025KT, TROP. DISTURBANCE. 60H: 2007/12/20 06 UTC: 21.7S/54.3E, MAX WIND=025KT, TROP. DISTURBANCE. 72H: 2007/12/20 18 UTC: 21.2S/52.9E, MAX WIND=025KT, TROP. DISTURBANCE. 2.B OTHER INFORMATIONS: T=2.5 AND CI=3.0- THE SYSTEM KEEPS ON TRACKING SOUTHWESTWARDS ALONG THE NORTHWESTERN EDGE OF THE SUBTROPICAL RIDGE BUT HAS SLOW DOWN A LITTLE BIT IN SPEED AS DEEP CONVECTION HAS REBUILT CLOSE TO THE CENTER DURING THE LAST FEW HOURS, INTENSITY IS KEPT AT 40 KT BUT THIS SHOULD BE GENEROUS ... AVAILABLE DYNAMICAL MODELS ADJUSTED TO THE 12Z POSITION SHOWS A WELL CLUSTERED ENSEMBLE OF SOLUTION WITH A GENERALLY SOUTHWESTWARDS TRACK UNTIL 18/12Z AND THEN A TURN TOWARD THE WEST FOLLOWED BY A WESTNORTHWESTWARDS MOTION 24 HOURS LATER AS RIDGE BUILTS BACK IN THE SOUTHWEST OF THE SYSTEM. IN FACT, NONE OF THE MODELS BRING THE CENTER SOUTH OF 22S. SO THIS WILL BE THE PHILOSOPHY FOR THIS ADVISORY WITH A FORECAST TRACK ON THE RIGHT OF THE PREVIOUS ONE AFTER 24 HOURS, AND ON THE SOUTHERN EDGE OF NWP MODELS ENVELOPE TRACKS. A WEAKENING TREND IS EXPECTED WITH COOLER SST, NORTHWESTERLY SHEAR, A STILL DRY ENVIRONMENT AND WEAKER LOWER LEVEL CONVERGENCE (AS THE MID-LATITUDE TROUGH PASSES SOUTHWARD).