What happened??

In spite of a massive thunderstorm in the early hours, after which there really shouldn't have been any rain left, the weather was so appalling this morning that I decided not to risk my 'real' camera as I don't have a waterproof housing for it. So I took this photo with my trusty little compact.

Can someone please explain what happened? How did we go from monsoon season to a glorious spring day in the space of a few hours??