Factors affecting SA WeatherSub-tropical Highs- SIH, SAHCold ocean current on west, warm on the east coastTemperature inversion over the plateauWeather disturbances such as mid- latitude cyclones and tropical cyclones.Topography- escarpment and plateau nature of the landscape.

Effect of relief and surface temperatures on weatherAir moving from the east to the west will lose its moisture- rises over the esxcarpment- relief effect.continental high is well developed during winter-low surface temps and descending air over the plateauDuring summer, land surface is hotter and a heat low develops over the land. This causes clear conditions over interior.

Pressure cells that occur over SA

Sub-tropical HighsCause an onshore flow of air over the countrySIH causes warmer moist air to move inlandSAH causes colder drier air to move inlandResult in stable, settled weather which in turn resdults in lower rainfallThey are not stationarySuring summer the SIH and SAH move so9uthwards away from the hotter land surfaceDuring winter they move northwards and are closer to the land.

Temperature inversion

Temperature inversionTemperature inversion consists of a layer of cold air. The height of this layer changes from winter to summer.It has an effect on rainfall prevents moist air from penetrating interior during winter.Cause clear conditionsMakes pollution levels worse over interior

Facts to remembercirculating anti-clockwise in Southern hemisphereRainfall decreases form east west across south AfricaHeat low occurs during summerContinental High dominates during winterTemperature inversion well developed in winter, not well developed during summer.