PJ2, weather radar
Extensive post PJ2, but for the completeness I would like to add "use of gain" and "black spots".
Gain: like other modern radars (post 1980's), the A330 radar is a low energy (weak) radar. Gain is the intensity of the radaroutput and is preset in auto-mode but that doesn't give a clear picture so often you use it in max gain; that pinpoints the cells more clearly.
Black spots: The radarsignals are reflected by the heavy precipitation in the cells, back to the radar so they never reach the area behind the cells. That means that you'll never exactly know what is behind the first storm untill you passed it.
Often these storm systems are lined up (like a squall line) so once you've passed the cells you are in the clear again, but these tropical storms in the ITF are so extensive that after avoiding the first couple of cells, more will turn up on your radar.
Indeed the radar is not made for weather penetration, but that applie to the cells only. Sometimes you really have to penetrate a weather system and use your radar to avoid the cells.