Contributors: A. Troccoli (WEMC), L. Sanger (WEMC), C. Goodess (WEMC), J. Ogonji (WEMC), L. Dubus (WEMC), R. Vautard F Pons (CEA), X. Jin (CEA), G. Levavasseur (CEA), R. Legrand (MF), L. Grigis (MF), S. Martinoni-Lapierre (MF), C. Viel (MF), S. Parey (EDF), B. Oueslati (EDF), Y-M. Saint-Drenan (ASSOCIATION POUR LA RECHERCHE ET LE DEVELOPPEMENT DES METHODES ET PROCESSUS INDUSTRIELS, ARMINES, FRANCE), J. Mendes (MO), J. Osborne (MO), G.Guentchev (MO)

Table of Contents

1. General

1.1. Description

Datasets of mean sea level pressure (SLP) are available for two streams i.e. Historical and Seasonal Forecasts. It may also be provided for the Projection stream at a later stage.

Historical: This dataset is based on the ERA5 reanalysis and retrieved from the CDS. No bias adjustment has been applied. Averages for NUTS0 (country) and NUTS2 (sub-country) areas have
been computed.

Seasonal forecasting: This dataset is currently available for ECMWF System 5, Météo-France ARPEGE System 7 and MetOffice GloSEA5 System 14. Seasonal Forecasts are retrieved from the CDS and are subsequently bias adjusted via quantile mapping. The forecast datasets are updated monthly when the raw forecast of each system is available. Averages for NUTS0 (country) are also provided.

1.2. Units

Hectopascal (hPa)

Historical: data on a standard 0.25° latitude/longitude grid for the C3S Energy domain, as well as NUTS0 and NUTS2 averages, will eventually be available via the C3S Energy/CDS demonstrator.

Seasonal Forecasts: Seasonal Forecast: the bias adjusted hindcast and forecast data will eventually be available via the C3S Energy/CDS demonstrator.

1.4. Data format

Historical: Gridded historical data are available as NetCDF files. NUTS0 and NUTS2 are available as CSV files

Seasonal Forecasts: Gridded seasonal forecast data are available as NetCDF files. NUTS0 are available as CSV files.

1.5. Keywords

Mean sea level pressure (SLP)
SLP is an instantaneous output variable.

1.6. Contact

copernicus-support@ecmwf.int

2. Dataset coverage

2.1. Geographic area

The C3S Energy domain is: 26.5° N to 72.5° N by 22.0° W to 45.5° E

2.2. Temporal resolution

Historical: 1-hour time step. Averages for daily, monthly, seasonal (DJF, MAM, JJA, SON) and annual are also computed for NUTS0 and NUTS2 mean values.

Seasonal Forecasts: 6-hour time step. Daily mean values (one file per ensemble member and per initialisation date) are also provided in order to feed energy models. One file is produced for each member and for each initialisation date. Monthly and seasonal (e.g. December-January-February, DJF) averages could be made available via the C3S Energy Demonstrator

2.3. Time period

Historical: 1979 to present (ca. 1 month behind real time); updated every month based on ERA5T data availability.

Seasonal Forecasts: The hindcasts cover the period 1993-2016 for the three models used by C3S Energy: ECMWF Sys5, Météo-France Sys7 and UK Met Office Sys14. ECMWF has all the month, MTFR SY07 currently covers October to April with the rest of the months to be completed by mid- May 2020 as this is a new system. METO SY14 ranges from June to April (notice that METO SY14 is a rolling release model, hindcast have to be computed each months). The forecasts updated have

been run every month from the first month of availability in the current version on the CDS:



Forecast availability

Forecast horizon


ECMWF Sys5

From January 2017

215 days, or 860 six-hourly time steps


MTFR Sys7

From October 2019

211 days, or 844 six-hourly time steps


METO Sys14

From June 2019

215 days, or 860 six-hourly time steps


2.4. Spatial resolution

Historical: 0.25° by 0.25° latitude/longitude. Data are also available as averages for more than 30 European countries and ca. 100 NUTS2 areas.

Seasonal Forecasts: 1° by 1° latitude/longitude and at country (NUTS0) scale. The underlying forecast systems run at different resolutions. Data are also available as averages for more than 30 European countries as NUTS0 areas.

3. Usage

3.1. Citation(s)

Historical: ERA5

Seasonal Forecast:

  1. ECMWF seasonal forecast system 5 technical description
  2. Météo-France seasonal forecast system 7 technical description
  3. Met Office

4. Lineage statement

4.1. Original data source

Historical: original gridded data come from the ERA5 Reanalysis

Seasonal Forecast: original data is available from the C3S Climate Data Store. See here for further details of the seasonal forecast models used.

4.2. Tools used in the production of indicators

Historical: data were retrieved and post-processed using python scripts.

Seasonal Forecasts: data were processed using standard open source python libraries, including numpy, scipy, matplotlib, and the SciTools packages iris and cartopy


5. Data Quality

Historical: ERA5 data have been compared to previously used ERA-Interim for consistency

Seasonal Forecast: forecast skill, such as measured by anomaly correlation, is performed and will be provided via the C3S Energy demonstrator. Maps representing the bias for different time-periods for each system are also provided, as well as graphs comparing hindcast dataset before and after bias-correction.


This document has been produced in the context of the Copernicus Climate Change Service (C3S).

The activities leading to these results have been contracted by the European Centre for Medium-Range Weather Forecasts, operator of C3S on behalf of the European Union (Delegation Agreement signed on 11/11/2014 and Contribution Agreement signed on 22/07/2021). All information in this document is provided "as is" and no guarantee or warranty is given that the information is fit for any particular purpose.

The users thereof use the information at their sole risk and liability. For the avoidance of all doubt , the European Commission and the European Centre for Medium - Range Weather Forecasts have no liability in respect of this document, which is merely representing the author's view.

6. Related articles

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