What causes multiple storms?

Johannesburg has just been hit by a series of unbelievable storms. About 5 thunderstorms moved through one after another, or the same one swirled round and round.

I've lived in Jo'burg going on 9 years now and I've never seen anything like this.

Pictures below (before the news!):

The calm before the storm (5pm)



The first time I've captured lightning on film - before the rain and hail storm hit and I ran for cover!



Two views of hailstones - about the size of golf balls - split through the force at which they hit.





My garden under a carpet of hail - the temperature immediately dropped to single figures.







I pity any one who was in the road at between about 19h00 and 22h00. I can hear the sirens as the rain still pelts down. I live in central Sandton.

I also feel sorry for any one traveling into Jo'burg by plane tonight - they're probably stuck in Bloemfontein now.

The damage in Johannesburg must be big. My skylights appear to be damaged - water is flooding the veranda ceiling and leaking from the light fittings. Jeez, I'd just recovered from a big financially straining month and now there will be another one. Storm 6 is just moving in now.