Reunion Island - Presentation Guillaume JUMAUX Météo-France – Indian Ocean Climatology Division SWIOCOF‐5, 19 to 23 September 2016 Seychelles Reunion island : Geographical situation Somalie 700 km east to Kenya Madagascar 180 km west-south-west to Mauritius Météo-France is the french national meteorological service. It is divided in 11 regions (7 in mainland France and 4 in overseas territories, including Reunion Island). Météo-France in Reunion Island is in charge of the data of Reunion Island, but also of Mayotte, and TAAF (scattered islands and austral and antarctic lands). Page 2 Reunion island : Stations Reunion island : Reunion- 2500 km²: 2500 km² Mountainous- Mountainous island island (3070 (3070 m) m) Trade- trade winds winds : contrast CyclonesEast/West world greatest rainfall (3930 mm, 3 days) - cyclones → world greatest rainfall amount in 3 days (3930 mm) Stations Network : - rainfall : ~ 90 stations 22 stations 1953-2015 - temperature : 47 stations 5 stations 1961-2015 Page 3 Mayotte : Stations Mayotte : Reunion : 2500 km² - 376Mountainous km² island (3070 m) - hillsTrade (660 winds m) Cyclones world greatest Stationsrainfall Network (3930 mm, : 3 days) - rainfall : ~ 12 stations 4 stations 1961-2015 - temperature : 7 stations 1 station 1951-2015 Page 4 Precipitation : long term means Annual rainfall amount : 500 mm to 10,000 mm in Reunion island 1,100 mm to 1,800 mm in Mayotte Page 5 Monthly Precipitation Heavy rainfalls, mainly during rainy season (Dec- Apr) : Very little precipitation during dry season (May-Nov), except in southern and eastern regions → water resources issue need a regular hydrological monitoring Page 6 Standard Precipitation Index (SPI) Page 7 Drought Intensity in Reunion island (based on SPI) No significant long-term trend - Too short sample (only 40 years) Page 8 - Strong variability with decennal cycles (90's, 10's are dry years) Rainy season 2015/2016 Dry season 2016 Page 9 Reunion Island : SPI in 2016 RAINY SEASON DRY SEASON SPI 4 months (Jan-Apr 2016) SPI 4 months (May-Aug 2016) Page 10 Seasonal Outlook Forecast (based on SPI) : OND 2015 Oct-Dec 2015 Oct-Dec 2015 Downscaled Seasonal Forecast Observations Page 11 4 regions How to do seasonal forecast in Reunion Island (JAS 2016) Page 12 An exemple : Downscaling model MSLP – Reunion Page 13 An exemple : Downscaling model MSLP – Reunion Page 14 An exemple : Downscaling model MSLP – Reunion ARPEGE FORECAST Page 15 An exemple : Downscaling model MSLP – Reunion ARPEGE FORECAST ReunionStations (51 members) Page 16 An exemple : Downscaling model MSLP – Reunion ARPEGE FORECAST ReunionStations (tercile prob.) Page 17 An exemple : Downscaling model MSLP – Reunion ARPEGE FORECAST ReunionStations Page 18 An exemple : Downscaling model CYCLONE ACTIVITY and track (exemple) Page 19 An exemple : Downscaling model CYCLOGENESIS ZONE (exemple) Page 20 THANK YOU Page 21.