https://phys.org/news/2018-10-nasa-aqua-satellite-rosa-remnants.html

Infrared satellite data captured on Tuesday, Oct. 2 at 6:05 a.m. EDT (1005 UTC the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA's Aqua satellite revealed the location of strongest storms with the coldest cloud top temperatures. MODIS found coldest cloud tops had temperatures near minus 63 degrees Fahrenheit (minus 53 degrees Celsius). NASA research has found that cloud top temperatures that cold have the capability to generate heavy rainfall.

Satellite images and surface observations indicate that Rosa has become a trough or an elongated area of low pressure with multiple swirls along its axis. Therefore, Rosa no longer qualifies as a tropical cyclone.