Radar data on AWS S3

The up-to-date weather radar from the FMI radar network is available as Open Data.

The following data is available for Finnish radar composite:

radar reflectivity (dbz), conversion: Z[dBZ] = 0.5 * pixel value - 32
rainfall intensity (rr), conversion: rr[mm/h] = 0.01 * pixel value
1 hour precipitation (rr1h), conversion: rr1h[mm] = 0.01 * pixel value
12 hour precipitation (rr12h)
24 hour precipitation (rr24h)

For single radars, the following data can be retrieved:

radar reflectivity (dbz)
radial velocity (vrad)
rain classification (hclass), conversion: 0=no signal, 1=non met, 2=rain, 3=wet snow, 4=dry snow, 5=graupel, 6=hail
cloud top height (etop_20), conversion: height[km] = 0.1 * pixel value - 0.1

Volume data from single radars are also available in HDF5-format. The data contain following parameters:

Logged horizontally-polarized total reflectivity factor (DBZH): Zh [dBZ]
Logged horizontally-polarized total (corrected) reflectivity factor (DBZHC): Zh [dBZ]
Logged polarized reflectivity factor (DBZX): Zh [dBZ]
Hydro Class, Hydrometeor classification (HCLASS)
Specific differential phase (KDP): K [degrees/km]
Differential phase (PHIDP): φ [degrees]
Correlation between Zh and Zv (RHOHV): ρhv [0-1]
Normalized signal-to-noise ratio (SNR): SNR [0-1]
Signal Quality Index (SQI): SQI [0-1]
Logged horizontally-polarized total eflectivity factor (TH): T [dBZ]
Logged horizontally-polarized total (TX): T [dBZ]
Radial velocity (VRAD): V [m/s]
Radial velocity (corrected) (VRADC): V [m/s]
Spectral width of radial velocity (WRAD): W [m/s]
Logged differential reflectivity (ZDR): ZDR [dBZ]
Logged differential reflectivity (corrected) (ZDRC): ZDR [dBZ]

The detailed information about HDF5-data can be found at OPERA HDF5 description

Radar data becomes available as soon as it's received from the radar and pre-processed into deliverable formats. Typically the most recent radar data was collected less than 5 minutes ago. Both single radar data and radar composites over Finland are made available.

FMI provides the same data via FMI Open data portal and AWS Public Datas Sets. The data is licensed by the Creative Commons Attribution 4.0 International license (CC BY 4.0).

Accessing the Data on AWS

The data is uploaded into two AWS S3 Buckets:

fmi-opendata-radar-geotiff
fmi-opendata-radar-volume-hdf5

The data is stored to the buckets with the following convention: /year/month/day/site/timestamp_site_prod.tif

Where timestamp site represents radar name or composite product name. Timestamp is given as ${year}${month}${day}${hour}${minute}

For example: 2020/09/08/FIN-DBZ-3067-250M/202009080000_FIN-DBZ-3067-250M.tif 2020/09/08/fiika/202009080000_fiika_DBZH.tif

Content of the buckets can be browsed here:

SNS

Public Amazon SNS topics are available for every new object added to the Amazon S3.

arn:aws:sns:eu-west-1:916174725480:fmi-opendata-radar-geotiff-object_created
arn:aws:sns:eu-west-1:916174725480:fmi-opendata-radar-volume-hdf5-object_created

For more information on subscribing to SNS topics, visit http://docs.aws.amazon.com/sns/latest/dg/SubscribeTopic.html.

For more information on the Amazon S3 event message structure, visit http://docs.aws.amazon.com/AmazonS3/latest/dev/notification-content-structure.html.

Tools to handle the data

GeoTIFF images may be handled with several tools QGIS and GDAL being the most common ones. Several python libraries can also be used to process the data. The following list is not comprehensive but gives some starting point:

HDF5 data may be processed, for example, with python libraries:

Here are some tutorials on how to handle the data: