@johnckealy I guess "infra+" means infrared+rain. It seems to be combined with radar detection data, since if you check "Radar" view on some rainy region you should see the matching of both views regarding rain clutter.
For me this is the best enhancement from Windy.com since my country Morocco was and still (for some dumb/incompetence reason) lacking Radar coverage for public use. Radar is the most vital feature in case of bad weather especially when you board the Atlantic! :)