In the wake of a strong El Niño phenomenon aggravating South Africa’s already dry conditions, no relief is yet to be seen, as an anticipated counter, La Niña, has been weakened to the point that “neutral conditions may not be completely ruled out”, the South African Weather Service (SAWS) said on Monday.
The El Niño last year severely exacerbated a years-long persisting drought that had resulted in 2015 being the driest year on record for South Africa since 1921.
“The recovery of South Africa from drought conditions may take some time, depending on rainfall and temperature conditions over the coming spring through summer 2016/17 season,” said SAWS long-range forecasting senior scientist Dr Asmerom Beraki at a media briefing at the agency’s Pretoria headquarters.
SAWS GM for operations Mnikeli Ndabambi explained that there was a “high level of uncertainty” over whether the water-stressed country would experience the amount of rainfall required to provide drought relief in the upcoming spring/summer season, which is generally the rain season.
“The situation is really bad,” he said, pointing to alarmingly low dam levels and skyrocketing temperatures, which reached record highs in 2015.
The recovery from the 2015/16 drought, which persisted across the bulk of South Africa, has been potentially stalled by forecast above-normal temperature tendencies in the coming seasons and the unlikelihood of a well-established La Niña.
This left climate-sensitive industries in a “delicate” situation, Beraki noted.
La Niña, which results in the cooling of sea-surface temperatures (SST) in the equatorial Pacific Ocean, traditionally offers up cooler, wetter conditions in contrast to the dry and hot conditions that follow El Niño’s warming of SST.
“When you have La Niña, you have a good season,” he commented.
“The disparity among forecast models shows the extent of uncertainty surrounding rainfall and temperature outlooks over our region, as well as the El Niño Southern Oscillation [or Enso] prediction [of neutral or weak La Niña].”
Generally, conditions over the Indian Ocean, where most of the moisture for South Africa’s summer rainfall originates, may not be “conducive” for rainfall activities during spring, with no certain indicators of SST anomalies smaller than to -0.5 °C over a three-month period, which indicates an incoming La Niña.
“Most climate models indicate the prospect of above normal rainfall conditions toward early summer, but with marginal confidence,” he added, noting that more reliable information could become available closer to the mid-summer.
“In the midst of the growing uncertainty surrounding all climate prediction models, close monitoring of particularly the SST anomaly tendencies over the adjacent oceans would be required to determine how the climate conditions of our region may evolve during the coming spring and summer season,” Beraki concluded.