The following describes data provided as part of the AGU publication: "On the Dependency of Hurricane and European Windstorm Hazards" by Michael Angus and Gregor Leckebusch
A description of the following four datafiles has been provided:
1) ETC_Track_Density.nc
2) TC_Track_Density.nc
3) Intensity_measures.nc
4) WiTRACK_IbTRACS_matched.csv 

If you have questions about any of the data below, please do not hesitate to contact the corresponding author Michael Angus, M.Angus@bham.ac.uk

1) ETC_Track Density.nc
A record of the model and observed track density for European windstorms. 
The following variables are contained within this version 4 netcdf file.
Ensemble_members. A list of the ECMWF Seas5 Seasonal Forecast (Johnson et al. 2019) ensemble members. For details on the construction of the ensemble, please see https://www.ecmwf.int/en/elibrary/17118-part-v-ensemble-prediction-system
Calendar_years. The year for which the model was initialised. For Track Density of European windstorms, event occur over December to February from the model run initalised in August. 
ETC_lon. Longitude values at 0.5 degrees
ETC_lat. Latitiude values at 0.5 degrees
ETC_ERAinterim_TD. The Track Density (number of storms in a given grid cell) for the above latitude and longitude grid, for the ERA-Interim dataset (Dee et al. 2011). 
ETC_SEAS5_TD. The Track Density (number of storms in a given grid cell) for the above latitude and longitude grid, for the SEAS5 dataset. 

PLEASE NOTE: Track density is performed on a filtered selection of European Windstorms, as described in Angus and Leckebusch (2020). As such, the North Atlantic storm track is restricted here to only those storms which impacted Europe directly. 

2) TC_Track Density.nc
A record of the model and observed track density for Atlantic TC events. 
The following variables are contained within this version 4 netcdf file.
Ensemble_members. A list of the ECMWF Seas5 Seasonal Forecast (Johnson et al. 2019) ensemble members. For details on the construction of the ensemble, please see https://www.ecmwf.int/en/elibrary/17118-part-v-ensemble-prediction-system
Calendar_years. The year for which the model was initialised. For Track Density of Atlantic Tropical Cyclones, event occur over August to October from the model run initalised in August. 
TC_lon. Longitude values at 0.5 degrees
TC_lat. Latitiude values at 0.5 degrees
TC_IBTrACS_TD.  The Track Density (number of storms in a given grid cell) for the above latitude and longitude grid, for the IBTrACS dataset (Knapp et al. 2010).
TC_ERAinterim_TD. The Track Density (number of storms in a given grid cell) for the above latitude and longitude grid, for the ERA-Interim dataset (Dee et al. 2011).
TC_SEAS5_TD. The Track Density (number of storms in a given grid cell) for the above latitude and longitude grid, for the SEAS5 dataset. 

3) Intensity_measures.nc
The following intensity measures of storm activity for both the Tropical Cyclone and European windstorms, are calculated as described in Angus and Leckebusch (2020). For details on normalised SSI, please see Leckebusch et al. (2007). 
The following variables are contained within this version 4 netcdf file.
Ensemble_members. A list of the ECMWF Seas5 Seasonal Forecast (Johnson et al. 2019) ensemble members. For details on the construction of the ensemble, please see https://www.ecmwf.int/en/elibrary/17118-part-v-ensemble-prediction-system
Calendar_years. The year for which the model was initialised. 
TC_nstorms. The number of Tropical cyclones per ensemble model year found in the SEAS5 model between August and October, following the WiTRACK description in Angus and Leckebusch (2020).
TC_SSSI. The total normalised Storm Severity Index of the season, per ensemble model year found in the SEAS5 model between August and October. 
TC_LiSSSI. The total normalised Storm Severity Index of the season for grid cells over land, per ensemble model year found in the SEAS5 model between August and October.
ETC_nstorms. The number of European Windstorms per ensemble model year found in the SEAS5 model between December and February, following the WiTRACK description in Angus and Leckebusch (2020).
ETC_SSSI. The total normalised Storm Severity Index of the season, per ensemble model year found in the SEAS5 model between December and February. 
ETC_LiSSSI. The total normalised Storm Severity Index of the season for grid cells over land, per ensemble model year found in the SEAS5 model between December and February. 

4) WiTRACK_IbTRACS_matched.csv 
A standard csv file
The first three columns provide information on stormID, name, start date of Tropical cyclone and depression events, as provided by the IBTrACS project (Knapp et al. 2010). 
The fourth column indicates how the event was classified, from sustained windfield data available from IBTrACS, for Figure 1d. 
The final column is given a tag of 1 if the event was matched to a WiTRACK track in ERA-Interim, with a tag of 0 given to unmatched events. For details on matching criteria, please see Angus and Leckebusch (2020). 

References: 
Dee, D.P., Uppala, S.M., Simmons, A.J., Berrisford, P., Poli, P., Kobayashi, S., Andrae, U., Balmaseda, M.A., Balsamo, G., Bauer, D.P. and Bechtold, P., 2011. The ERA‐Interim reanalysis: Configuration and performance of the data assimilation system. Quarterly Journal of the royal meteorological society, 137(656), pp.553-597.
Johnson, S.J., Stockdale, T.N., Ferranti, L., Balmaseda, M.A., Molteni, F., Magnusson, L., Tietsche, S., Decremer, D., Weisheimer, A., Balsamo, G. and Keeley, S.P., 2019. SEAS5: The new ECMWF seasonal forecast system. Geoscientific Model Development, 12(3).
Angus, M. and Leckebusch, G.C., 2020, On the Dependency of Hurricane and European Windstorm Hazards, Geophysical Research Letters, In Publication
Knapp, K.R., Kruk, M.C., Levinson, D.H., Diamond, H.J. and Neumann, C.J., 2010. The international best track archive for climate stewardship (IBTrACS) unifying tropical cyclone data. Bulletin of the American Meteorological Society, 91(3), pp.363-376.
Leckebusch, G.C., Ulbrich, U., Fröhlich, L. and Pinto, J.G., 2007. Property loss potentials for European midlatitude storms in a changing climate. Geophysical Research Letters, 34(5).