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 : 4/7/20072008 1.A TROPICAL DISTURBANCE 7 2.A POSITION 2008/01/08 AT 0600 UTC : 20.2S / 55.1E (TWENTY DECIMAL TWO DEGREES SOUTH AND FIFTY FIVE DECIMAL ONE DEGREES EAST) 3.A DVORAK ANALYSIS : 1.5/1.5 /S 0.0/24 H 4.A CENTRAL PRESSURE : 1004 HPA 5.A MAX AVERAGE WIND SPEED (10 MN) : 20 KT 6.A EXTENSION OF WINDS BY QUADRANTS (KM): 7.A FIRST CLOSED ISOBARE (PRESSURE / AVERAGE DIAM): 1008 HPA / 1100 KM 8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: MEDIUM 1.B FORECASTS: 12H: 2008/01/08 18 UTC: 20.7S/54.5E, MAX WIND=020KT, TROP. DISTURBANCE. 24H: 2008/01/09 06 UTC: 21.8S/53.9E, MAX WIND=020KT, TROP. DISTURBANCE. 36H: 2008/01/09 18 UTC: 22.9S/53.5E, MAX WIND=020KT, TROP. DISTURBANCE. 48H: 2008/01/10 06 UTC: 23.9S/53.1E, MAX WIND=020KT, TROP. DISTURBANCE. 60H: 2008/01/10 18 UTC: 24.6S/52.7E, MAX WIND=020KT, TROP. DISTURBANCE. 72H: 2008/01/11 06 UTC: 25.2S/51.9E, MAX WIND=020KT, TROP. DISTURBANCE. 2.B OTHER INFORMATIONS: T=CI=1.5+. CENTRE IS RELOCATED SLIGHTLY NORTHWARDS. THIS WEAK CIRCULATION WITH A SMALL SIZE IS RESPONSIBLE FOR THE BAD WEATHER OVER THE MASCARENES AREA. ASSOCIATED CONVECTIVE ACTIVITY IS VERY FLUCTUATING AND NORTHEASTWARDS AWAY FROM THE CENTRE DUE TO THE SOUTHWESTERLY VERTICAL WINDSHEAR. LLC IS RATHER POORLY DEFINED BUT THE CENTRE CAN BE DETECTED ON THE RADAR IMAGERY AT LA REUNION THIS LOW IS POORLY ANALYZED BY NUMERICAL MODELS, CURRENT TRACK AND INTENSITY FORECASTS ARE RATHER UNCERTAIN. THE FRENCH MODEL ALADIN IS THE ONLY ONE TO PROPERLY ANALYZES THIS LOW, BUT WITH A TOO STRONG INTENSITY. ENVIRONNEMENTAL CONDITIONS REMAIN UNFAVORABLE; VERTICAL WINDSHEAR REMAINS FAIR, WITH A GOOD UPPER LEVEL DIVERGENCE, BUT NO POLEWARDS LOW LEVEL INFLOW. NO INTENSIFICATION IS EXPECTED. SUBTROPICAL HIGH PRESSURES ARE QUASI-STATIONARY AROUND 70E, WITH A PERSISTANT RIDGE EAST OF THE SYSTEM. THE EXTRATROPICAL LOW NEAR 37S/49E AT 0600Z IS EXPECTED TO TRACK SOUTHSOUTHEASTWARDS, TRACKING SOUTH OF THE PERSISTANT HIGH. THIS SHOULD BUILD A RIDGE OVER THE MASCARENES ISLANDS THAT IS SPATIALLY FLUCTUATING ACCORDING THE DIFFERENT MODEL. SPEED AND DIRECTION OF THE MINIMUM WILL DEPEND ON THE EVOLUTION OF THIS RIDGE. AT LONG RANGE, SYSTEM SHOULD SLOW DOWN AND TRACK WESTWARDS ON THE NORTHERN EDGE OF THE REBUILDING SUBTROPICAL HIGH PRESSURES IN THE SOUTHWEST. THE INTENSITY OF THIS SYSTEM DOES NOT JUSTIFY ISSUANCE OF REGULAR WARNINGS.