What's going on with Rio Vista, CA radar?
This blob has been visible for weeks from the web view. I've also seen it on the Rainy Days app on Android.
Oddly, I don't see it on the Android version of the Windy app, the WeatherBug app, or Accuweather's or NOAA's radar view.
@markping That is likely some interference on the radar disk itself. it's common with Doppler radars. Most other websites filter out interference like that by default. Windy shows the raw data so things like that might be common in some places.