Radar characteristics
"The signal needs to be of just the right strength to be partially reflected thus showing the WX. The snag is the weaker beam also suffers attenuation."
This is not true. All radar beams suffer attenuation. A stronger beam can make it through the precip when weaker beams may not. The radar processes the echo after the beam has been transmitted, so a stronger beam will always produce a stronger echo. Radars also attempt to compensate for the attenuation (your mileage may vary).
A mention has been made here of radar and super-cells. Super-cells are rotating thunderstorms that are unlikely at ITCZ latitudes - they are what produce most tornadoes, especially in the US midwest. Super-cells may have a bounded weak echo region (a rapid updraft with a weak radar echo). I don't think that's what's going on here.
But... an ordinary very strong thunderstorm cell can also produce weak echos in the updraft. Monsoon storms are likely to be pulse-severe - they pop up, rain in their own inflow, and die, followed by another one triggered by the outflow from that rain. To a normal observer, it looks like one storm moving along, but the reality is more complex. On a satellite picture, the only clue may be a series of overshooting tops (colder spots) in a general area of cold tops.