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 : 11/13/20052006 1.A MODERATE TROPICAL STORM 13 (ELIA) 2.A POSITION 2006/04/14 AT 1200 UTC : WITHIN 30 NM RADIUS OF POINT 14.5S / 88.0E (FOURTEEN DECIMAL FIVE DEGREES SOUTH AND EIGHTY EIGHT DECIMAL ZERO DEGREES EAST) 3.A DVORAK ANALYSIS : 3.0/3.5 /W 0.5/6 H 4.A CENTRAL PRESSURE : 987 HPA 5.A MAX AVERAGE WIND SPEED (10 MN) : 45 KT 6.A EXTENSION OF WINDS BY QUADRANTS (KM): 30 KT NE: 080 SE: 200 SO: 200 NO: 080 7.A FIRST CLOSED ISOBARE (PRESSURE / AVERAGE DIAM): 1008 HPA / 700 KM 8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: DEEP 1.B FORECASTS: 12H: 2006/04/15 00 UTC: 15.5S/86.7E, MAX WIND=045KT, MODERATE TROP. STORM. 24H: 2006/04/15 12 UTC: 16.5S/85.8E, MAX WIND=040KT, MODERATE TROP. STORM. 36H: 2006/04/16 00 UTC: 17.5S/85.0E, MAX WIND=040KT, MODERATE TROP. STORM. 48H: 2006/04/16 12 UTC: 18.7S/84.2E, MAX WIND=035KT, MODERATE TROP. STORM. 60H: 2006/04/17 00 UTC: 19.8S/83.5E, MAX WIND=030KT, TROP. DEPRESSION. 72H: 2006/04/17 12 UTC: 21.0S/82.7E, MAX WIND=030KT, BECOMING EXTRATROPICAL. 2.B OTHER INFORMATIONS: T=3.0+ AND CI=3.5- THE SYSTEM WAS ORGANIZED IN CURVED BAND PATTERN LAST NIGHT BUT SEEMS TO BECOME IN CDO PATTERN ORGANIZATION NOW WITH A LLCC LIGHTLY DEPHASED ON THE NORTHWESTERN MAIN CLUSTER'S EDGE. SYSTEM SEEMS TO BE CONSTRAINTED BY NORTH-NORTHWESTERLY VERTICAL WINDSHEAR (AT 10KT, ACCORDING TO THE CIMSS) POLARWARDS DIVERGENCE REMAINS GOOD IN RELATIONSHIP WITH AN EFFICIENT UPPER LEVEL OUTFLOW CHANNEL; BUT THE LOWER LAYER CONVERGENCE IS WEAK, THE MONSOON FLOW IS NOT ESTABLISHED NORTH OF THE SYSTEM. THE POTENTIAL FOR AN INTENSIFICATION IS THUS LIMITED. THE LLCC IS ASYMMETRIC, WITH MAXIMUM WINDS LOCATED IN THE SOUTHERN SEMI-CIRCLE DUE TO THE GRADIENT EFFECT WITH THE SUBTROPICAL HIGH PRESSURES. THE SYSTEM IS EXPECTED TO KEEP ON TRACKING MAINLY SOUTHWESTWARDS DURING THE NEXT 72 HOURS, IN RELATIONSHIP WITH HIGHS IN THE MID-LEVEL EXISTING EAST OF THE SYSTEM AND THEN TOWARDS A TROUGH SHIPPING EASTWARDS IN THE SOUTH. ECMWF NWP MODEL FORECASTS AN ALTERNATIVE WESTWARDS SCENARIO WHICH WOULD BE POSSIBLE IF THE SYSTEM CONTINUES TO BE SHEARED AND THUS BECOME UNDER THE INFLUENCE OF THE LOW LAYER STEERING AND THE TRADE WINDS FLOW. SOUTH OF 18S AND EAST OF 80E, ENERGETICS ENVIRONMENT IS LESS AND LESS FAVOURABLE DUE TO SEA SURFACE TEMPERATURE LESS THAN 26.0 C.