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 : 33/11/20072008 1.A SEVERE TROPICAL STORM 11 (IVAN) 2.A POSITION 2008/02/15 AT 0600 UTC : WITHIN 20 NM RADIUS OF POINT 15.2S / 55.7E (FIFTEEN DECIMAL TWO DEGREES SOUTH AND FIFTY FIVE DECIMAL SEVEN DEGREES EAST) 3.A DVORAK ANALYSIS : 4.0/4.0 /D 0.5/24 H 4.A CENTRAL PRESSURE : 975 HPA 5.A MAX AVERAGE WIND SPEED (10 MN) : 60 KT 6.A EXTENSION OF WINDS BY QUADRANTS (KM): 30 KT NE: 450 SE: 300 SO: 260 NO: 200 50 KT NE: 070 SE: 070 SO: 070 NO: 070 7.A FIRST CLOSED ISOBARE (PRESSURE / AVERAGE DIAM): 1006 HPA / 1000 KM 8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: DEEP 1.B FORECASTS: 12H: 2008/02/15 18 UTC: 15.6S/54.6E, MAX WIND=070KT, TROPICAL CYCLONE. 24H: 2008/02/16 06 UTC: 15.9S/53.3E, MAX WIND=075KT, TROPICAL CYCLONE. 36H: 2008/02/16 18 UTC: 16.2S/52.3E, MAX WIND=080KT, TROPICAL CYCLONE. 48H: 2008/02/17 06 UTC: 16.7S/51.4E, MAX WIND=085KT, TROPICAL CYCLONE. 60H: 2008/02/17 18 UTC: 17.0S/50.6E, MAX WIND=090KT, INTENSE TROP. CYCL.. 72H: 2008/02/18 06 UTC: 17.6S/49.1E, MAX WIND=080KT, OVERLAND. 2.B OTHER INFORMATIONS: T=4.0+ AND CI=4.0+ IVAN HAS TRACKED WEST-SOUTHWESTWARDS AT 10 KT DURING THE PAST 6 HOURS. LATEST MICROWAVE IMAGERY (0157Z WINDSAT AND 0415Z SSMIS F16) SHOW A WELL DEFINED LLCC WITH A NEAR CLOSED EYE BUT IMAGERY IN THE 85 GHZ CHANNEL SHOW THAT DEEP CONVECTION IS NOT CONSOLIDED AROUND THE CENTER. MAX WINDS ARE ESTIMATED AT 60 KNOTS AND WITH THE CURRENT IMPROVMENT OF THE OVERALL CONFIGURATION, IVAN SHOULD BE A TROPICAL CYCLONE LATER TODAY. 12Z NWP MODEL RUNS ARE IN VERY GOOD AGREEMENT AS THEY HAVE NOW A MORE WESTWARDS SOLUTION AT A SLIGHTY FASTER SPEED. SUBTROPICAL RIDGE APPEARS NOW TO HOLD THE SYSTEM ON A GENERALLY WESTSOUTHWARDS TRACK ALONG THE NORTHERN EDGE OF THE SUBTROPICAL RIDGE. IT SHOULD KEEP ON REGULARY INTENSIFYING WITHIN A FAVORABLE ENVIRONMENT (HIGH OCEAN HEAT CONTAIN AND DECREASING SHEAR). SPREAD ON THE ECMWF ENSEMBLE FORECAST SYSTEM HAS REDUCED AGAIN SENSITIVELY ON THE LAST RUN... GIVEN SOME CONFIDENCE ON THE GUIDANCE. SO THIS FORECAST IS CLOSE TO THE ECMWF AND ECMWF ENSEMBLE PREDICTION SYSTEM SOLUTIONS. IVAN IS NOW A SERIOUS THREAT FOR THE CENTRAL EAST COAST OF MADAGASCAR.