README.md

---
license: cc-by-4.0
tags:
- climate
pretty_name: DWD ICON-EU Forecasts
size_categories:
- 1K<n<10K
---

# Dataset Card for DWD ICON-EU Forecast

This dataset is comprised of forecasts from the German Weather Service's (DWD) [ICON-EU model](https://www.dwd.de/EN/ourservices/nwp_forecast_data/nwp_forecast_data.html).
From 2020-01-01 to March 2023 this archive contains a subset of the ICON-EU variables. From March 2023 to the present, all variables are included. 
This archive includes 4 model runs per day (00, 06, 12, 18). 
This data is an archive of the publicly available data from https://opendata.dwd.de/weather/nwp/, converted to Zarr format with Xarray. 
No other processing of the data is performed.

Please note that the data from 2020-01-01 to March 2023 is of a slightly different shape compared to the data from March 2023 to the present. 
Please see [this GitHub issue](https://github.com/dynamical-org/reformatters/issues/183) for more details.

> [!NOTE]  
> We plan to move this archive to dynamical.org to make it easier and faster for you to access this data. See [the announcement](https://huggingface.co/datasets/openclimatefix/dwd-icon-eu/discussions/14) for more info.

> [!WARNING]  
> We will stop updating this ICON-EU archive on Hugging Face six months after the ICON-EU dataset goes live on dynamical.org. See [the announcement](https://huggingface.co/datasets/openclimatefix/dwd-icon-eu/discussions/14) for more info.

## Dataset Details

- **Curated by:** Jacob Bieker, Sol Cotton, Open Climate Fix
- **License:** Creative Commons BY 4.0. To quote [DWD's "legal notice"](https://www.dwd.de/DE/service/rechtliche_hinweise/rechtliche_hinweise_node.html): "All freely accessible geodata and geodata services, as well as DWD services defined as high-value datasets (HVD),
  may be reused under the terms of the Creative Commons BY 4.0 ([CC BY 4.0](https://creativecommons.org/licenses/by/4.0/)) license, provided the source is acknowledged.
   Geodata includes all provided meteorological weather and climate information with a location reference."

## Example

2 meter temperature in Kelvin. Init time = 2022-01-01T00. Step = 0.

![temperature](temperature.png)

### NWP variables archived for 2020-01-01 to March 2023:

Shape: step: 93, latitude: 657, longitude: 1097, isobaricInhPa: 6

Number of variables: 27

| Key | Long name | Unit | Dimensions |
|:---:|:---------:|:----:|:----------:|
| alb_rad | Albedo | % | step, latitude, longitude |
| aswdifd_s | Downward diffusive short wave radiation flux at surface (mean over forecast time) | W m-2 | step, latitude, longitude |
| aswdir_s | Downward direct short wave radiation flux at surface (mean over forecast time) | W m-2 | step, latitude, longitude |
| cape_con | Convective Available Potential Energy | J kg-1 | step, latitude, longitude |
| clch | Cloud Cover (0 - 400 hPa) | % | step, latitude, longitude |
| clcl | Cloud Cover (800 hPa - Soil) | % | step, latitude, longitude |
| clcm | Cloud Cover (400 - 800 hPa) | % | step, latitude, longitude |
| clct | Total Cloud Cover | % | step, latitude, longitude |
| h_snow | Snow depth | m | step, latitude, longitude |
| omega | Vertical velocity | Pa s**-1 | step, isobaricInhPa, latitude, longitude |
| pmsl | Pressure reduced to MSL | Pa | step, latitude, longitude |
| relhum_2m | 2 metre relative humidity | % | step, latitude, longitude |
| runoff_g | Water Runoff | kg m-2 | step, latitude, longitude |
| runoff_s | Water Runoff (s) | kg m-2 | step, latitude, longitude |
| t | Temperature | K | step, isobaricInhPa, latitude, longitude |
| t_2m | 2 metre temperature | K | step, latitude, longitude |
| t_g | Temperature (G) | K | step, latitude, longitude |
| td_2m | 2 metre dewpoint temperature | K | step, latitude, longitude |
| tot_prec | Total Precipitation | kg m**-2 | step, latitude, longitude |
| u | U component of wind | m s**-1 | step, isobaricInhPa, latitude, longitude |
| u_10m | 10 metre U wind component | m s**-1 | step, latitude, longitude |
| v | V component of wind | m s**-1 | step, isobaricInhPa, latitude, longitude |
| v_10m | 10 metre V wind component | m s**-1 | step, latitude, longitude |
| vmax_10m | maximum Wind 10m | m s-1 | step, latitude, longitude |
| w_snow | Snow depth water equivalent | kg m**-2 | step, latitude, longitude |
| ww | weather interpretation (WMO) | Numeric | step, latitude, longitude |
| z0 | Surface roughness | m | step, latitude, longitude |

### NWP variables archived for March 2023 onwards:

Shape: step: 79, latitude: 657, longitude: 1377, isobaricInhPa: 20

Number of variables: 63

| Key | Long name | Unit | Dimensions |
|:---:|:---------:|:----:|:----------:|
| alb_rad | Forecast albedo | % | step, latitude, longitude |
| alhfl_s | Time-mean surface latent heat flux | W m**-2 | step, latitude, longitude |
| ashfl_s | Time-mean surface sensible heat flux | W m**-2 | step, latitude, longitude |
| asob_s | Time-mean surface net short-wave radiation flux | W m**-2 | step, latitude, longitude |
| asob_t | Time-mean top net short-wave radiation flux | W m**-2 | step, latitude, longitude |
| aswdifd_s | Downward diffusive short wave radiation flux at surface (mean over forecast time) | W m-2 | step, latitude, longitude |
| aswdifu_s | Upward diffusive short wave radiation flux at surface ( mean over forecast time) | W m-2 | step, latitude, longitude |
| aswdir_s | Downward direct short wave radiation flux at surface (mean over forecast time) | W m-2 | step, latitude, longitude |
| athb_s | Time-mean surface net long-wave radiation flux | W m**-2 | step, latitude, longitude |
| athb_t | Time-mean top net long-wave radiation flux | W m**-2 | step, latitude, longitude |
| aumfl_s | Time-mean U-component of atmospheric surface momentum flux | N m**-2 | step, latitude, longitude |
| avmfl_s | Time-mean V-component of atmospheric surface momentum flux | N m**-2 | step, latitude, longitude |
| cape_con | Convective Available Potential Energy | J kg-1 | step, latitude, longitude |
| cape_ml | Convective Available Potential Energy, mean layer | J kg-1 | step, latitude, longitude |
| clc | Cloud cover | % | step, isobaricInhPa, latitude, longitude |
| clch | Cloud Cover (0 - 400 hPa) | % | step, latitude, longitude |
| clcl | Cloud Cover (800 hPa - Soil) | % | step, latitude, longitude |
| clcm | Cloud Cover (400 - 800 hPa) | % | step, latitude, longitude |
| clct | Total Cloud Cover | % | step, latitude, longitude |
| clct_mod | Modified cloud cover for media | Numeric | step, latitude, longitude |
| cldepth | Modified cloud depth for media | Numeric | step, latitude, longitude |
| fi | Geopotential | m**2 s**-2 | step, isobaricInhPa, latitude, longitude |
| h_snow | Snow depth | m | step, latitude, longitude |
| hbas_con | Height of Convective Cloud Base above msl | m | step, latitude, longitude |
| htop_con | Height of Convective Cloud Top above msl | m | step, latitude, longitude |
| htop_dc | Height of top of dry convection above MSL | m | step, latitude, longitude |
| hzerocl | Height of 0 degree Celsius isotherm above msl | m | step, latitude, longitude |
| omega | Vertical velocity | Pa s**-1 | step, isobaricInhPa, latitude, longitude |
| pmsl | Pressure reduced to MSL | Pa | step, latitude, longitude |
| ps | Surface pressure | Pa | step, latitude, longitude |
| qv_2m | 2 metre specific humidity | kg kg**-1 | step, latitude, longitude |
| qv_s | Specific Humidity (S) | kg kg-1 | step, latitude, longitude |
| rain_con | Convective rain rate | kg m**-2 s**-1 | step, latitude, longitude |
| rain_gsp | Large scale rain rate | kg m**-2 s**-1 | step, latitude, longitude |
| relhum | Relative humidity | % | step, isobaricInhPa, latitude, longitude |
| relhum_2m | 2 metre relative humidity | % | step, latitude, longitude |
| rho_snow | Snow density | kg m**-3 | step, latitude, longitude |
| runoff_g | Water Runoff | kg m-2 | step, latitude, longitude |
| runoff_s | Water Runoff (s) | kg m-2 | step, latitude, longitude |
| snow_con | Convective snowfall water equivalent | kg m**-2 | step, latitude, longitude |
| snow_gsp | Large-scale snowfall water equivalent | kg m**-2 | step, latitude, longitude |
| snowlmt | Height of snow fall limit above MSL | m | step, latitude, longitude |
| synmsg_bt_cl_ir10.8 | Synth. Sat. brightness temperature cloudy | K | step, latitude, longitude |
| t | Temperature | K | step, isobaricInhPa, latitude, longitude |
| t_2m | 2 metre temperature | K | step, latitude, longitude |
| t_g | Temperature (G) | K | step, latitude, longitude |
| t_snow | Snow temperature (top of snow) | K | step, latitude, longitude |
| tch | Turbulent transfer coefficient for heat (and Moisture) | Numeric | step, latitude, longitude |
| tcm | Drag coefficient | Numeric | step, latitude, longitude |
| td_2m | 2 metre dewpoint temperature | K | step, latitude, longitude |
| tmax_2m | Time-maximum 2 metre temperature | K | step, latitude, longitude |
| tmin_2m | Time-minimum 2 metre temperature | K | step, latitude, longitude |
| tot_prec | Total Precipitation | kg m**-2 | step, latitude, longitude |
| tqc | Total Column-Integrated Cloud Water | kg m-2 | step, latitude, longitude |
| tqi | Total Column-Integrated Cloud Ice | kg m-2 | step, latitude, longitude |
| u | U component of wind | m s**-1 | step, isobaricInhPa, latitude, longitude |
| u_10m | 10 metre U wind component | m s**-1 | step, latitude, longitude |
| v | V component of wind | m s**-1 | step, isobaricInhPa, latitude, longitude |
| v_10m | 10 metre V wind component | m s**-1 | step, latitude, longitude |
| vmax_10m | Time-maximum 10 metre wind gust | m s**-1 | step, latitude, longitude |
| w_snow | Snow depth water equivalent | kg m**-2 | step, latitude, longitude |
| ww | weather interpretation (WMO) | Numeric | step, latitude, longitude |
| z0 | Forecast surface roughness | m | step, latitude, longitude |

### Dataset Source

- **Raw files:** https://opendata.dwd.de/weather/nwp/

Note: DWD deletes the grib2 files after 24 hours.

## Uses

This data is intended for use in renewable energy forecasting, weather forecasting, and anything that can use high-quality weather forecasts over Europe.


## Dataset Structure

The dataset is comprised of one Zarr file per forecast initialization time, and each forecast has a time horizon of 48 to 120 hours. The files are located at data/year/month/day/YYYYMMDDHH.zarr.zip.

## Dataset Creation

### Curation Rationale

The DWD ICON-EU model provides high-quality, high-resolution forecasts for European weather that is also publicly available and free of charge. The model should generally outperform
NOAA's GFS forecast model, and has a higher temporal and spatial resolution. The main downside of this model is that the files are only available for a short period publicly, so this dataset
was setup to provide a public archive of the forecasts for use by researchers in many fields, but especially renewable energy forecasting and weather forecasting.

### Source Data

The source data is the grib2 files from the DWD Open Data Server.

#### Data Collection and Processing

The data is collected every day, around 6-8 hours after forecast initialization time to ensure the forecast is finished running before the data is pulled. The grib2 files are opened
with Xarray and collated into a single Xarray Dataset, with one data variable per ICON variable. Surface variables have "_s" appended to their names to differentiate them from multi-level variables.
The Dataset is then written to Zarr using "ocf_blosc2" to encode and compress the variables. No scaling or changing of the variables values is performed.

#### Who are the source data producers?

German Weather Service (DWD)


### Recommendations

These files can be opened directly from HuggingFace, and streamed in with Xarray. HuggingFace is fairly slow though, so the recommended way would be to download the files you want
and open them locally. In either case, to access the data you can do the following

```python
import ocf_blosc2
import xarray as xr
data = xr.open_zarr("path/to/zarr/file")
print(data)
```


## Dataset Card Contact

OCF Data Team: [email protected]