Rain only expected in November
There is optimism about a good rainy season, but it will start late.
09 August 2021 | Weather
Little to no rainfall is expected for spring, while outlooks are positive for summer rainfall starting from about November.
This is according to Santam climatologist Johan van den Berg, who added that temperatures will still be below average until at least the second part of August, especially minimum temperatures, while frost may occur until the end of the month.
He explained that the probability for La Niña development has increased and there is an about 60 to 70% probability that it will develop from September to October. “This is positive for summer rainfall.”
He added that favourable Indian Ocean temperatures in combination with La Niña can further enhance the rainfall probabilities and can even assist in an earlier onset of rainfall for the summer.
According to Van den Berg, El Niño–Southern Oscillation (ENSO) has been in a neutral state since about April.
“There was an upgrade in the probability for occurrence to just under 70% for the development of a La Niña event to reign from about October 2021 to March 2022.”
The probability for an El Niño event is about zero, with an about 30% to 40% probability of neutral conditions to continue.
“This increased probability from about 50% to 70% for La Nina conditions is very significant, especially for this time of the year,” Van den Berg said.
It is most likely that conditions in the Indian Ocean will be the main driving force of climate and weather patterns over southern Africa in the next summer season, but if the expected La Nina event intensifies, the combined effect can be responsible for increased probabilities of above average rainfall.