ARE FRONTS FROM MID-LATITUDE DEPRESSIONS REACHING SOUTHERN PARTS OF AFRICA?
Mid-latitude depressions occur over the Southern Ocean between Africa and the Antarctic continent. Cold fronts from these weather systems often extend as far as southern Africa. They can be seen on satellite images as distinct bands of cloud, and they are marked on weather charts. TODAY: Todays 06:00UTC weather chart from South Africa shows no fronts close to South Africa and this is borne out by the satellite images. CAN YOU SEE ANY SMALL TO MEDIUM-SIZED CUMULUS CLOUDS? These clouds occur where there is strong heating of the ground by the sun. They show up as tiny white specks on visible satellite images but do not show up on infra-red images. They show up on visible images because sunlight is reflected from them. They do not show up on infra-red images because their vertical growth is rather small. The colder an object is, the whiter it appears on an infra-red image. Thus, tall cumulonimbus clouds appear white, because their tops are high and therefore cold. The tops of small to medi
