Looks like this page is removed entirely.
https://web.archive.org/web/20160611075614/https://www.ncdc.noaa.gov/wct/newfeatures.phpMaybe they are trying to hide the AWS S3 buckets the data could be found in:
> Through cooperative activities as a part of NOAA's Big Data Project, the full historical archive of NEXRAD Level-2 data is available for direct download from the Amazon S3 storage. The Toolkit's 'Data Selector' has been enhanced to provide direct access to the NEXRAD data that resides in the cloud infrastructures. 