What happened
When the then British Prime Minister, Harold Macmillan, spoke of the “Winds of Change” the last thing in mind would have been the weather. But, after all, wind is weather and as such is (like the poor) always with us. But the local example of the “winds of change” saw the irruption of windy conditions on to a scene where placidity had held sway. A check on the calendar proves that this is August, there is a reputation for wind in this month. The core of the surface anticyclone has nestled over much of southern Africa for some weeks: it's still there, but increasing daytime warmth tends to tighten the isobars somewhat.

Tightened isobars mean that the air pressure gradient steepens and the experience is wind. By world-wide standards, our wind experiences are limited. The gales of the “Roaring Forties” among other such areas within the Temperate Climate belt and its adjacent areas are unknown in our latitudes. Even the Lüderitz South-easter is downscale to such persistent wind flows.
The Beaufort Scale rates our experiences as “breezes” of varying strengths. But for us it means “the August winds”. They began about a week ago and are likely to continue until we have got used to them and the anticyclonic core weakens and gives way to the rising warmth (surface heating at least) of Spring.
Otherwise, the gentle transformation from the (calendar) depths of winter proceeded.
The broader picture has changed little. The oceanic pressure patterns show intense vortices, core air pressures (down to the 930 h Pa levels) here and there, interspersed with unusual ridges linking the mobile surface anticyclones with Antarctic cells and the west-to-east passage goes generally unhindered..The Equatorial scene shows temperature neutrality dominant in the mid and western Pacific, equanimity in the Indian Ocean: feeding the Indian Monsoon, the ITCZ holding its own across the Sahel. So, from a distance all is well on the weather front.
What's coming.
A well-marked cold front and a closely-associated upper-air trough crossed the Cape on Thursday. This development is strong enough to affect airflows well ahead of its map position. Such airflows include strong, turbulent winds in the upper levels (where Jet-aviation flies). The term Clear Air Turbulence (CAT) can make itself felt. No cloud in the sky but the bumpiness making a corrugated dirt-road seem like a smooth ride. Such turbulence can, at worst, break an aircraft! Wind speeds are above a mere 100 knots, even to 200 to 300 knots in the extreme, and will be adjacent to a Jet Stream which divides the air mass between Tropical and Temperate upper air components.
On the surface, this new system brings colder air to the south, even extending to central Namibia, during Friday but retreating during Saturday to return to a warmer range by Sunday and into the new week.
The succeeding anticyclone quickly pushes behind the cold front and its parent vortex, thus limiting the northward drive of the cold air. The anticyclonic ridge extends to the ice-shelf, so there will be some modification of the polar air as it is swept northward to our latitudes and those immediately to our south.
As this anticyclone extends, as a ridge first, then breaking off into a new strengthening cell off the southeastern coasts, so there will be an invasion of cooler, moister air across the eastern sub-continent.
Cloud is possible in the northeast.
The next active system appears by Wednesday with more wind!
With dry air and wind the risk of veld fires, like Gibeon districts' of this last week, persists.