Drought-stricken areas such the Lowveld are likely to receive above average rainfall and possible floods due to a possible La Niña phenomenon.
La Niña is the cooling of sea surface temperatures in the tropical pacific, which occurs roughly every three to five years, lasting from 6 to 24 months. On average, half of El Niño events are followed by a La Niña, which typically affects global climate patterns in the opposite way El Niño does.
For Lowvelders, it is important to note that there is increased likelihood of cyclones forming in the Mozambique channel with associated potential landfall and flooding.
What is the current forecast for La Niña?
Current forecasts indicate that the onset of a La Niña episode may start between August and October 2016 and there is a 55 to 60% that it would persist until the beginning of 2017.
Consequences of La Niña?
A La Niña phenomenon generally affects the same regions that are impacted by El Niño, with opposite climatic consequences. Areas such as the Lowveld which experienced dry conditions (below-average rainfall and/or increased temperature) during El Niño, for instance, tend to receive above-average rainfall and in some cases lower temperatures.
While the climatic phenomenon usually peaks in intensity between October and January, changes to climatic patterns and their related impacts on food security and agriculture can happen both before and after the peak. It is possible that La Niña could develop as early as August, in which case it might already start affecting the growing seasons in some parts of the world from September 2016.
Since La Niña would most likely impact regions that have already been affected by El Niño, the food security situation could further deteriorate and protract into 2018. In the event of a “positive” La Niña, it is important to highlight that the actual full effect of above-average rainfall will not be felt until the next harvest – i.e. the end of 2016 (if La Niña comes early) or by mid-2017 (if La Niña occurs later).
- In South Africa, La Niña is generally associated with increased probability of above-average rainfall from around November to April, which corresponds to the main cropping season for most countries in the region.
- Enhanced rainfall could speed up the regeneration of pasture land and lead to above-average crop production for the summer harvest.
Potential negative effects
- Positive effects of La Niña on crop production would only be able to alleviate the current high levels of food insecurity from February 2017 onwards, when the main maize crop matures and is subsequently harvested.
- If excessive, precipitation would increase the risk of localized flooding which could wash away seeds, damage or destroy standing crops, increase livestock morbidity and mortality and damage infrastructure.
* This information is based on a recent report by the Food and Agriculture Organization of the United Nations. Download it here.