Thanks to ever more precise, more targeted forecasts

As an essential prerequisite for weather forecasting and climate studies, the observation of atmospheric phenomena is essential for characterising past and future climate and for better anticipating extreme weather events by feeding ever more refined digital weather prediction models.

A major evolution in the accuracy of digital weather prediction models

Since 2 July 2019, Météo-France has refined the resolution of its models. This increased accuracy of forecasts, which zoom in on Europe and the near Atlantic in an unequalled way up to D+4, is accompanied by major advances such as the determination of new parameters to describe "sensitive weather" (visibility, type of precipitation, cloud height) or the significant improvement of parameters already produced (wind gusts during thunderstorms in particular). The most emblematic changes are significant increases in the horizontal resolution of global systems. Thus, the Arpege model is refined to 5 km over the metropolis and 24 km in the South Pacific. The formation of small-scale structures, such as fronts or clouds associated with areas of intense precipitation, is treated more realistically, as are the interactions with the surface, which are also better described through the relief or nature of the ground.

Metop-C and Aeolus improve forecast quality

Eumetsat's Metop-C polar-orbiting satellite, the third and last in the series, was launched from Kourou on 7 November 2018. Like its predecessors which are still available, it carries a large number of measuring instruments dedicated to operational meteorology. Following the in-orbit verification activities carried out by Eumetsat, its first data were gradually assimilated into Météo-France models between July 2019 and January 2020 with a significant impact on forecast quality.

Calibration of the Copernicus satellites: deployment of 50 high-precision drifting buoys from Brest

Météo-France successfully organised the deployment of the first 50 high-precision drifting buoys designed to provide reference measurements over the world's oceans to calibrate the satellites of the Copernicus programme. Météo-France has been deploying drifting buoys in the world's oceans since the 1980s, taking advantage of the establishment's overseas locations, for example from Reunion Island in the Indian Ocean (DIROI). These developments testify to Météo-France's continued strong involvement in surface ocean monitoring and contribute to the preparation of the United Nations Decade of Ocean Sciences for Sustainable Development (2021-2030).

Observation from connected objects

To improve its knowledge of meteorological phenomena and make progress in forecasting their impacts, a partnership has been consolidated with the automotive supplier Continental to develop a weather warning service that makes use of information from vehicles. This collaboration contributes to the global approach to evaluate the potential of measurements from connected objects (cars, weather stations, etc), which is set to expand.

Modernisation of the state climate network

Météo-France has always used the services of volunteers whose mission is to observe the weather. They do this by means of a climatological station that can be installed in the city, in the countryside, a private garden, a farmer's field or on the premises of a company, etc. Several times a day, they record temperatures and rainfall and then describe the weather at the time of the reading. These data, once transmitted to Météo-France, are integrated with other observation data and help to understand the heterogeneity of local climates. They are also used to initialise and validate climate forecast models. In 2019, Météo-France upgraded the number of climatological stations and installed a proportion of automated stations, in particular according to local geographical characteristics and complementarity with the local observation network. In 2019, 1,797 climatological stations in metropolitan France and 229 overseas make up the network with 1,645 volunteers located throughout the territory. We would like to thank them for that! In order to strengthen links with users and meet its needs in terms of meteorological observations, Météo-France also offers a module on its mobile app that allows mobile users to enter their own weather observations. This participatory science operation has proved successful, with more than 11,000 sensitive weather observations every day in 2019.

Progress in the anticipation of extreme events and climate projections depends on the computing power available to the establishment and the expertise of its scientists to make the most of it.

Météo-France makes official the arrival of a new supercomputer to refine weather forecasts and climate analysis

Météo-France is renewing its intensive computing system which will be operational in October 2020. The solution selected after an 18-month competitive dialogue is based on the Sequana XH2000 platform, developed by Bull (an Atos subsidiary) and manufactured in Angers. The computing power gain factor will be more than 5, enabling more accurate weather forecasts geographically and over time. In particular, this acquisition will gradually improve the forecasting of dangerous phenomena, with a gain of 1 to 2 hours on forecasts; improve geographical accuracy and thus better identify risks, by going down to an infra-departmental scale; take into account more observations and new types of observations such as connected objects.

This new computing power will also enable France to strengthen its ability to contribute to simulations and forecasts of the consequences of climate change at the European and global level. The first delivery of the supercomputer took place on Tuesday 19 November 2019 at the Météopole. A 35-ton semi-trailer deposited the first components (4 computer cabinets, 2 internal network racks, 2 service node cabinets, etc). It will be commissioned in 2020.