Wet, chilly summer here to stay for a while, due to La Niña
Above normal rainfall is predicted for the rest of summer.
A meteorological threshold, for example 50 millimetres of rain in 24 hours, is not necessarily needed to be met in order for a warning to be issued. If the anticipated rainfall is expected to have an impact, an alert will be issued. Picture for illustration: iStock
If you’ve been wondering what’s the deal with these cold summer days, you are not alone.
We’ve officially entered the summer season, but there’s a good chance that some South African’s still have their winter blankets and heaters out. Fortunately, there is an explanation for the fluctuating hot and cold temperatures South Africa has been experiencing these past few weeks.
In a water-scarce country, rainfall is always welcome, and the good news is, wet weather patterns are here to stay for the time being.
According to the SA Weather Service, an oceanic and atmospheric phenomenon, known as La Niña is responsible for our cold summer days.
La Niña is the colder counterpart of El Niño, as part of the broader El Niño–Southern Oscillation climate pattern.
The name La Niña is Spanish for “the girl”, and El Niño, meaning “the boy”.
The SA Weather Service reports that large parts of the country received normal to above-normal rainfall during the spring season.
“It was, in particular, the western interior that received relief from drought conditions,” explained the Weather Service.
“Good rainfall conditions continued into the month of December 2021, with most of the country receiving above-normal rainfall during the first ten days of December.
“La Niña conditions are expected to continue during the summer season, and the predictions for rainfall over the larger part of the country are probabilities of above-normal rainfall during the January-February-March, February-March-April and March-April-May 2022 seasons,” said SA Weather Service.
La Niña weather patterns unpredictable
According to the World Meteorological Organisation (WMO) La Niña has developed for the second consecutive year and is expected to last into early 2022, influencing temperatures and precipitation.
La Niña refers to the large-scale cooling of the ocean surface temperatures in the central and eastern equatorial Pacific Ocean, coupled with changes in the tropical atmospheric circulation, namely winds, pressure and rainfall.
It usually has the opposite effects on weather and climate as El Niño, which is the warm phase of the so-called El Niño Southern Oscillation (ENSO).
But even with mounting data and improving computer models, El Niño, La Niña and the Southern Oscillation remain difficult to predict.
(Compiled by Narissa Subramoney)
