Why does rain fall with different intensity during a storm?

Question

Recently in my area (Dallas/Fort Worth) it has been raining quite frequently. While observing the rain, a question I've been wondering about for a long time came to mind -- Why does rain fall with different intensity during a storm? Today, for example, it started drizzling approximately an hour ago. After a few minutes, there was a sudden, torrential downpour. This lasted for approximately three minutes, then the intensity fell. At that point, it was raining harder than a drizzle, but less than a torrent. After that it went back to torrenting, then drizzling, etc...

Why does this happen?

Answer 1

In the case of storms particularly in the revolving storms(like hurricane) clouds are arranged in bands which are in spiral form;hence there will be gaps (where there are no cloud formations) between these bands.When these bands pass through a place one after another, there is bound to be variations in the rainfall intensity.

Answer 2

A Storm (ANY Storm) is a wonderfully complex System. It's CONSTANTLY in Transition... -growing, weakening, changing it's position, evolving- etc.. And what goes into & comes OUT OF that storm- changes accordingly, depending upon what's going ON within it. A building Thunderstorm takes on alot of moisture, then suddenly dumps alot of it all in a rush- only for that downpour to suddenly get "cut off"- when a new Updraft within the Storm- sends all those raindrops back Up! (this is one of the Processes that causes Hail, in fact). This can happen repeatedly in a T-Storm- until the whole System begins to weaken- & it rains itself out... Pretty Cool- huh ?!  :)