GWL-REA_ERA5 Catalogue of Grosswetterlagen based on reanalysis data (ERA5)
DOI for Scientific and Technical Data
10.5676/DWD/GWL-REA_V1.6_ERA5_GLP
Title
GWL-REA_ERA5 Catalogue of Grosswetterlagen based on reanalysis data (ERA5)
Subtitle
GWL-REA_V1.6_ERA5_GLP - Catalogue of Grosswetterlagen
Citation
James, Paul; Ostermöller, Jennifer, "GWL-REA_ERA5 Catalogue of Grosswetterlagen based on reanalysis data (ERA5) GWL-REA_V1.6_ERA5_GLP - Catalogue of Grosswetterlagen version v2026.01." Deutscher Wetterdienst, 2026, doi:10.5676/DWD/GWL-REA_V1.6_ERA5_GLP.Creators
James, Paul (Deutscher Wetterdienst); Ostermöller, Jennifer (Deutscher Wetterdienst)Acknowledgement
The classification method was developed by Paul James (Deutscher Wetterdienst) and is provided by DAS-Basisdienst.
Publication Date
2026
Version
v2026.01
Publisher
Deutscher Wetterdienst
Summary
GWL-REA (Grosswetterlagen from reanalyses) is a new algorithmic method for classifying daily synoptic weather types over Central Europe, based on the well-known set of Hess-Brezowsky Grosswetterlagen (GWL). The method was designed by Paul James (Deutscher Wetterdienst) and has been continuously refined in terms of quality and efficiency.
The basis of the classification are correlations to reference patterns for each Grosswetterlage. In this context, the number of reference patterns has been strongly increased to account for within-type variability more accurately. The correlation coefficients are now systematically modified via the use of Lamb Weather Type (LWT) statistics in order to improve the correspondence of the classified GWLs to their given nomenclature. Beside this, an advanced AI module was deployed to optimize the classification further and strongly improve the correspondence between the GWL's cyclonicity classes with areal mean daily precipitation over Germany and neighbouring regions.
Compared to the classical Hess-Brezowsky Grosswetterlagen with 29 classes, GWL-REA contains 30 classes, as the GWL “Brücke Mitteleuropa” (Zonal Ridge across Central Europe) is divided into a cyclonic and an anticyclonic type.
The catalogue contains a temporally filtered time series to which a low-pass filter was applied to guarantee a minimum duration of three days to achieve a better readability of the catalogue (GLP, Grosswetterlagen Low Pass Filter).
The catalogue is based on input data from ERA5 (Hersbach et al., 2020).
The basis of the classification are correlations to reference patterns for each Grosswetterlage. In this context, the number of reference patterns has been strongly increased to account for within-type variability more accurately. The correlation coefficients are now systematically modified via the use of Lamb Weather Type (LWT) statistics in order to improve the correspondence of the classified GWLs to their given nomenclature. Beside this, an advanced AI module was deployed to optimize the classification further and strongly improve the correspondence between the GWL's cyclonicity classes with areal mean daily precipitation over Germany and neighbouring regions.
Compared to the classical Hess-Brezowsky Grosswetterlagen with 29 classes, GWL-REA contains 30 classes, as the GWL “Brücke Mitteleuropa” (Zonal Ridge across Central Europe) is divided into a cyclonic and an anticyclonic type.
The catalogue contains a temporally filtered time series to which a low-pass filter was applied to guarantee a minimum duration of three days to achieve a better readability of the catalogue (GLP, Grosswetterlagen Low Pass Filter).
The catalogue is based on input data from ERA5 (Hersbach et al., 2020).
Spatial Coverage
Europe
Temporal Coverage
from: 1940-01-01 until:Resource Type
dataset
Resource Format
Resource Size
20 kB
Resource Access
| Download | Format | Info |
|---|---|---|
| GWL-REA_v1.6_ERA5_GLP_catalogue.csv | opendata | Catalogue of Grosswetterlagen (GWL). The data is separated by ";" and structured as follows: Date (YYYY-mm-dd) ; GWL number ; GWL abbreviation. For a detailed description of the GWL, see GWL-REA_v1.6_ERA5_GLP_description.csv |
Supplemental Information
GWL-REA uses a circular weighting around Germany.
| GWL-REA_v1.6_ERA5_GLP_description.csv |
|---|
| Description of the 30 weather types from the catalogue GWL-REA_v1.6_ERA5_GLP_catalogue.csv |
Publications
Contact
Referat Hydrometeorologische Beratungsleistungen (KU41)Deutscher Wetterdienst
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Deutschland
e-mail: Hydromet@dwd.de
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