The Next Generation Weather Radar (NEXRAD) is a network of 160 high-resolution Doppler radar sites that detects precipitation and atmospheric movement and disseminates data in approximately 5 minute intervals from each site. NEXRAD enables severe storm prediction and is used by researchers and commercial enterprises to study and address the impact of weather across multiple sectors.
The real-time feed and full historical archive of original resolution (Level II) NEXRAD data, from June 1991 to present, is now freely available on Amazon S3 for anyone to use. This is the first time the full NEXRAD Level II archive has been accessible to the public on demand. Now anyone can use the data on-demand in the cloud without worrying about storage costs and download time.
We are making NEXRAD data available as part of our research agreement with the US National Oceanic and Atmospheric Administration (NOAA) to enable new product development and analysis.
This page includes information on data structure and sample use cases to help you get started. You can find much more detailed information about NEXRAD Level II data from NOAA and other online sources.
The NEXRAD Level II archive data is hosted in the “noaa-nexrad-level2” Amazon S3 bucket in S3’s US East region. The address for the public bucket is: https://noaa-nexrad-level2.s3.amazonaws.com
Each volume scan file of archival data is available as an object in Amazon S3. The basic data format is:
- <Year> is the year the data was collected
- <Month> is the month of the year the data was collected
- <Day> is the day of the month the data was collected
- <NEXRAD Station> is the NEXRAD ground station (map of ground stations)
- <filename> is the name of the file containing the data. These are compressed files (compressed with gzip). The file name has more precise timestamp information.
All files in the archive use the same compressed format (.gz). The data file names are, for example, KAKQ20010101_080138.gz. The file naming convention is:
- GGGG = Ground station ID (map of ground stations)
- YYYY = year
- MM = month
- DD = day
- TTTTTT = time when data started to be collected (GMT)
Note that the 2015 files have an additional field on the file name. It adds “_V06” to the end of the file name. An example is KABX20150303_001050_V06.gz.
The full historical archive from NOAA from June 1991 to present is available
The NEXRAD Level II real-time data is hosted in the “unidata-nexrad-level2-chunks” Amazon S3 bucket in S3’s US East region. The address for the public bucket is: https://unidata-nexrad-level2-chunks.s3.amazonaws.com/
Each chunk of each volume scan file is its own object in Amazon S3. The basic data format is:
- <Site> is the NEXRAD ground station (map of ground stations)
- <Volume_Number> is the volume id number (cycles from 0 to 999)
- <YYYYMMDD> is the date of the volume scan
- <HHMMSS> is the time of the volume scan
- <CHUNKNUM> is the chunk number
- <CHUNKTYPE> is the chunk type
All files in the real-time feed use bzip2 compression. Additional documentation on the chunks is available on the last page, B-1, of this Interface Control Document.
We have set up public Amazon SNS topics that create a notification for every new object added to the Amazon S3 chunks and archive buckets for NEXRAD on AWS. To start, you can subscribe to these notifications using Amazon SQS and AWS Lambda. This means you can automatically add new real-time and near-real-time NEXRAD data into a queue or trigger event-based processing if the data meets certain criteria such as geographic location.
The Amazon Resource Name (ARN) for the real-time data is arn:aws:sns:us-east-1:684042711724:NewNEXRADLevel2Object
The ARN for the archive data is arn:aws:sns:us-east-1:811054952067:NewNEXRADLevel2Archive
This open source java tool from students at Purdue University streamlines the process of running a MapReduce job with NEXRAD data on AWS.
A day-long course on how to use Python and Amazon EC2 to work with NEXRAD data was provided at the 2017 American Meteorological Society meeting. Full course materials and documentation are available in the AMS Short Course on Interacting with Radar Data in The Cloud GitHub repository.
Unidata has made the NEXRAD Level II archive data available via their THREDDS Data Server (TDS) to users with .edu domains. Visit the TDS page for more information on using this software. This Jupyter notebook shows you how to use Python to access the NCEI radar archive on Amazon S3 through Unidata's THREDDS server.
||National Oceanic and Atmospheric Administration|
|Category||Earth Science, Sensor Data, Natural Resource, Meteorological|
|Format||Binary format specific to NEXRAD|
|Storage Service||Amazon S3|
In US Standard (N. Virginia)
|Update Frequency||New Level II data is added as soon as it is available.|