(If you are piloting a plane or a boat, please consult with the SAWS or your nearest regional office… I am not at liberty to give forecasts for high risk activities…)
As you have been noticing, there has been a lot more rain than usual is areas that are dominated by summer rainfalls, while the south western parts of South Africa (winter rainfall areas) are dominated by drier weather.
What’s to follow is a short explanation about the reasons behind these phenomenons and I will try to keep it as simple as possible without leaving out too much detail.
There is a band of clouds over the equator known as the Inter-Tropical Convergence Zone (ITCZ). This is a relatively narrow and mostly zonal synoptic scale zone of low pressures where wind discontinuity is encountered and where into the surface winds in the tropics converge. Thus the trade winds from the north and south come together and cause strong convective activity to occur. The ITCZ is not stationary and migrates with the seasons, being located more south during southern hemisphere (SH) summers and more north during SH winters. Now with this migration, it also pushes other systems further south or north. The Congo Air Boundary (CAB) is one such system and which is causing the increase in rainfall.
Figure 1 1200 UTC 24 January 2011
There is a strong high pressure cell (Figure 1) located over the interior of Southern Africa that together with the CAB is bringing tropical air from the tropics down to SA. This together with the warm, moist air from the Indian Ocean is mixing and causing a lot of convective systems (thunderstorms) to be formed.
The world is also experiencing La Nina at the moment which means that Southern Africa will have wetter than normal conditions.
Figure 2 0600 UTC 24 January 2011
Figure 3 1200 UTC 24 January 2011
Figures 2 and 3 are satellite photos taken 6 hours apart and are just showing the cloud layers. The light blue clouds are ice crystals and are therefore high clouds and do not produce significant precipitation. The white clouds are water droplets and are therefore low or middle clouds and it is these clouds that produce precipitation. And of course, you can see the dry conditions that the south western areas are experiencing. Blue clouds on top of white clouds are an indication of thunderstorms that have developed to great heights.
Unfortunately for some these wet conditions are here to stay till end of February beginning of March.
. Martin Brundle said during one of the races how teams employ locals to go out into the neighboring towns/hills and sit and wait, if they saw rain coming phone home and alert. Also loved how Webber and his race engineer got the jump on the other teams and by "looking out the window" and changing to the correct tires because of that 
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