The summer rainfall regions of South Africa are in for wet weather, as an episode of the weather phenomenon La Niña settles in for the rest of the season, the South African Weather Service said on Wednesday.
“La Niña will intensify in January and February over the summer rainfall areas but should clear in March,” senior forecaster Jan Vermeulen said.
La Niña (meaning “the girl”) is also sometimes known as “anti-El Niño” — as its effects are usually the opposite of those experienced during El Niño (“the boy”) which heralds a dry period.
La Niña and El Niño result from the interaction between ocean and atmospheric conditions.
While El Niño in Southern Africa is associated with warmer than usual seas in the eastern Pacific, La Niña — usually preceded by an El Niño period — is triggered by cooler ocean temperatures.
The two are mutually dependent and they are collectively referred to as the El Niño Southern Oscillation (ENSO).
El Niño is associated with dry conditions but the onset on an episode of La Niña leads to normal or above normal precipitation.
The last half of a La Niña episode is typically wetter so the rainy weather experienced lately through most of the country could be expected to intensify towards the end of the year and into the beginning of 2012. — Sapa