Radar is radar. If the target has enough of a cross section it’s going to show up. C-130’s can dump butt loads of chaff and that stuff hangs out there forever. I’ve seen chaff clouds that look huge on the screen.
There isn't enough chaff on a C-130 to begin to create that kind of image on a weather radar or any other type of radar. I have over 5000 hours in the C-130 and am familiar with the chaff and flare capabilities they have. You want enough chaff to confuse a radar-guided missile homing in on you. You don't want so much that you show every radar in an entire enemy country where you are and what direction you're heading.
Biggest radar mystery since the Michigan State Police
clocked a willow tree doing 108 MPH back in the 80’s.