What happened?
A low pressure system was present over the central sub-continent, covering more or less Botswana, western Zambia and western Zimbabwe. Above it at the upper level is a weak high pressure system. This differential generates its own unique dynamic i.e. air moves from high pressure to low pressure, in this case descending, thereby compressing. In this process energy is released leading to very high ambient temperatures on the surface. From Wednesday onward, this system slipped to the east, advecting moist air on its western side bringing some relief to the very hot conditions experienced across the north.
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