https://phys.org/news/2018-08-nasa-imerg-heavy-rainfall-eastern.html

Continuing heavy rain also fell in Texas over the weekend. This provided some badly needed drought relief in that area but heavy rainfall also resulted in over three dozen people being rescued on Sunday from flood waters along the Nueces River in south-central Texas.

The Global Precipitation Measurement mission or GPM's constellation of satellites provided rainfall data to provide the rainfall estimates. GPM is a joint mission between NASA and the Japan Aerospace Exploration Agency, JAXA.