Originally Posted by
Propduffer
Although I don't know the location or the type of radar that "Tracked" QZ8501 I don't believe it possible for even heavy rain to attenuate the return from either passive or primary radar.
Secondary radar is not normally attenuated by rain but primary radar is always attenuated by rain. The shorter the wavelength the more attenuation. An ATC radar of the order of 10cm can be close on completely useless in heavy rain despite technical mitigations.