There has again been a lot of cumulonimbus activity over southern Africa, and again in an arc with a sharp southern boundary. The effect of the south-easterly trade winds is to drive water away from the coast, whereupon it is replaced by cool water from below. In Madagascar, it is tropical cyclone season. We wait with interest to see if they experience a cyclone during the MetLink project. If so, we hope it does not approach too closely.
Tropical cyclones are destructive weather phenomena.
They bring very strong winds and very heavy rain. At La Reunion island, there have been some phenomenal falls of rain from cyclones over the years - like 160 cm in 24 hours on one occasion. There is still high pressure north-west of Tristan da Cunha, but it has declined to 1017 mb. Not far to the south of Tristan, however, there is a deep depression giving South Georgia and Bouvet Island strong winds. But, then, those islands are in the so-called 'Roaring Forties'.