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 : 13/8/20082009 1.A MODERATE TROPICAL STORM 8 (GAEL) 2.A POSITION 2009/02/05 AT 0000 UTC : WITHIN 30 NM RADIUS OF POINT 18.1S / 58.5E (EIGHTEEN DECIMAL ONE DEGREES SOUTH AND FIFTY EIGHT DECIMAL FIVE DEGREES EAST) MOVEMENT : WEST-SOUTH-WEST 7 KT 3.A DVORAK ANALYSIS : 3.5/3.5 /D 1.0/24 H 4.A CENTRAL PRESSURE : 987 HPA 5.A MAX AVERAGE WIND SPEED (10 MN) : 45 KT RADIUS OF MAXIMUM WINDS (RMW) : 50 KM 6.A EXTENSION OF WINDS BY QUADRANTS (KM): 30 KT NE: 240 SE: 300 SO: 200 NO: 300 7.A FIRST CLOSED ISOBARE (PRESSURE / AVERAGE DIAM): 1009 HPA / 1000 KM 8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: DEEP 1.B FORECASTS: 12H: 2009/02/05 12 UTC: 18.5S/56.4E, MAX WIND=060KT, SEVERE TROP. STORM. 24H: 2009/02/06 00 UTC: 18.6S/54.3E, MAX WIND=065KT, TROPICAL CYCLONE. 36H: 2009/02/06 12 UTC: 19.0S/52.5E, MAX WIND=080KT, TROPICAL CYCLONE. 48H: 2009/02/07 00 UTC: 20.1S/51.4E, MAX WIND=090KT, INTENSE TROP. CYCL.. 60H: 2009/02/07 12 UTC: 21.0S/51.2E, MAX WIND=100KT, INTENSE TROP. CYCL.. 72H: 2009/02/08 00 UTC: 21.7S/51.2E, MAX WIND=100KT, INTENSE TROP. CYCL.. 2.B OTHER INFORMATIONS: T=CI=3.5- LOCATION OF THE CENTER STILL REMAINS RATHER APPROXIMATIVE BUT WITHIN THE NEXT HOURS LLCC IS EXPECTED TO TRACK WITHIN LA REUNION DOPPLER RADAR'S RANGE ALLOWING MORE PRECISE MONITORED LOCATIONS. AN UPPER LEVEL OUTFLOW CHANNEL IS BUILDING POLEWARD AS SHOWED BY NORTHWARDS AND NORTHEASTWARDS CIRRUS OUTFLOW REVEALING AN IMPROVING UPPER LEVEL DIVERGENCE. MICROWAVE SSMIS 04/1600Z AND TRMM 04/1756Z REVEALS A LOW LEVEL CIRCULATION CENTER LOCATED ON THE WESTERN EDGE OF THE HEAD OF THE CURVED BAND. DESPITE WINDSHEAR HAS WEAKENED WITHIN THE PAST 24 HOURS, A SLIGHT CONSTRAINT STILL EXISTS. 04/1414Z QUIKSCAT SWATH SHOWED A BROAD WEAK WIND AREA NEAR THE CENTER (50NM DIAMETER FROM WEST TO EAST). THIS RATHER BAD ORGANIZATION OF LOW LEVEL VORTEX IS CONFIRMED BY MICROWAVE 37GHZ CHANNELS AND SEEMS THERFORE NOT OPTIMAL FOR A RAPID INTENSIFICATION WITHIN THE NEXT HOURS. THIS FIX IS THEREFORE A LITTLE BIT CONSERVATIVE DESPITE THE IMPROVING SATELLITE INFRARED PRESENTATION AND INTENSITY FORECAST FOR THE NEXT 24 HOURS IS ALSO LIMITED TO A CLIMATOLOGIC RATE. GAEL IS STILL TRACKING ALONG THE STEERING FLOW OF A MID-LEVEL RIDGE PRESENT IN THE SOUTH OF THE SYSTEM, WHICH SHOULD THEREFORE KEEP ON TRACKING WESTWARD FOR THE NEXT 24 HOURS. BEYOND, A WEAKNESS IN THE MID-LEVEL RIDGE SHOULD CURVE THE TRACK SOUTHWESTWARDS. CURRENT FORECAST TRACK IS CLOSE TO THE GENERAL CONSENSUS. ENVIRONMENTAL CONDITIONS SHOULD BECOME EXCELLENT BEYOND 24 TO 36 HOURS (GOOD LOW LEVEL INFLOW, HIGH SSTS, GOOD UPPER LEVEL DIVERGENCE AND A WEAK WINDSHEAR) MAURITIUS AND LA REUNION ISLANDS LIKELY SHOULD NOT BE CONCERNED BY THE ACTIVE PART OF THE SYSTEM AS IT TRACKS IN THE NORTH OF THE MASCARENES ISLANDS. THESE ISLANDS SHOULD HOWEVER CLOSELY MONITOR THE PROGRESS OF THE SYSTEM. RELATED TO THE EVOLUTION OF THE SYSTEM, INTEREST ALONG THE EASTERN COAST OF MADAGASCAR SHOULD CLOSELY MONITOR THE PROGRESS OF THIS SYSTEM TOO.