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 : 10/3/20072008 1.A MODERATE TROPICAL STORM 3 (BONGWE) 2.A POSITION 2007/11/20 AT 1800 UTC : WITHIN 20 NM RADIUS OF POINT 11.9S / 73.2E (ELEVEN DECIMAL NINE DEGREES SOUTH AND SEVENTY THREE DECIMAL TWO DEGREES EAST) 3.A DVORAK ANALYSIS : 2.5/3.5 /W 1.0/12 H 4.A CENTRAL PRESSURE : 988 HPA 5.A MAX AVERAGE WIND SPEED (10 MN) : 45 KT 6.A EXTENSION OF WINDS BY QUADRANTS (KM): 30 KT NE: 100 SE: 170 SO: 200 NO: 170 7.A FIRST CLOSED ISOBARE (PRESSURE / AVERAGE DIAM): 1010 HPA / 900 KM 8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: MEDIUM 1.B FORECASTS: 12H: 2007/11/21 06 UTC: 12.7S/71.6E, MAX WIND=040KT , MODERATE TROP. STORM. 24H: 2007/11/21 18 UTC: 13.2S/70.3E, MAX WIND=045KT , MODERATE TROP. STORM. 36H: 2007/11/22 06 UTC: 13.4S/69.0E, MAX WIND=050KT , SEVERE TROP. STORM. 48H: 2007/11/22 18 UTC: 13.5S/67.6E, MAX WIND=050KT , SEVERE TROP. STORM. 60H: 2007/11/23 06 UTC: 13.4S/66.2E, MAX WIND=045KT , MODERATE TROP. STORM. 72H: 2007/11/23 18 UTC: 13.0S/64.8E, MAX WIND=040KT , MODERATE TROP. STORM. 2.B OTHER INFORMATIONS: T=2.5- AND CI=3.5-. TODAY "BONGWE" HAS UNDERGONE A SEVERE DECAY OF ITS RELATED CONVECTION DUE TO THE PERSISTENCE OF A SLIGHT EASTERLY WIND SHEAR BUT MORE PROMINENTLY BECAUSE OF THE INTRUSION OF DRY AIR FROM THE WEST AND NORTH OF ITS CIRCULATION WRAPPING INTO THE INNER CORE OF THE STORM. THE BIG QUESTION FOR THE INTENSITY FORECAST IS TO KNOW IF THIS DRY AIR INTRUSION IS JUST A TRANSIENT EVENT OR NOT AND WHETHER THE STORM MAY BE ABLE TO REJUVENATE AS BENEFITING FROM RATHER FAVOURABLE OTHER ENVIRONMENTAL CONDITIONS FOR THE NEXT 36 TO 48 HOURS (GOOD UPPER DIVERGENCE AND WEAKENING SHEAR).... PRESENT FORECAST CALL NOW FOR A SLIGHT DECREASE IN STRENGH FOR THE NEXT 24 HOURS FOLLOWED BY SOME MARGINAL RE-INTENSIFICATION BRINGING BACK BONGWE TO SEVERE TROPICAL STORM STATUS.