Guys yes INMET and the military have websites where they make weather radar available for free for Brazil such as:

https://www.redemet.aer.mil.br/?i=produtos&p=radares-meteorologicos
http://sigma.cptec.inpe.br/radar/
http://www.cemaden.gov.br/mapainterativo/

Please Windy see if you can get a feed from those sites ! It would be awesome to have it on the great Windy.com app