As severe thunderstorms, hail storms and heat waves continue to wreak havoc in South Africa, we put our focus on why various parts of the country are experiencing such different and intense weather phenomena.
Severe thunderstorms are leaving a trail of destruction in the north-eastern areas of the country. This includes a tornado in the Lekwa local municipality in Mpumalanga, as well as hailstorms in parts of the City of Joburg, with the most severe of these in the suburbs of Midrand.
Severe damage to property, including housing and other structures, as well as motor vehicles, has been reported.
Meanwhile, in the rest of the country, temperatures soar up to 40°C.
The SA Weather Service (Saws) has warned of temperatures between 30°C and 40°C for the Cape Town metropole and other parts of the Western Cape province for Tuesday and Wednesday.
The city’s Disaster Risk Management Centre advises the public to take precautions to mitigate any potential health and general safety impacts from the predicted weather.
But why is this happening?
In a statement released on Tuesday, the Saws explained that there is a weather situation where a low-pressure system is located over the central parts of the country, and there is a high-pressure system to the east.
This specific arrangement is causing moisture at lower levels of the atmosphere to move into the north-eastern parts of the country. As a result, conditions are favourable for the formation of thunderstorms in those areas.
“Thunderstorms started developing over south-eastern North West province and the northern Free State early in the afternoon, moving north-eastwards towards Gauteng and south-western Mpumalanga. Once it was observed on the radar and satellite that some of these thunderstorms were becoming severe, a warning was issued for the southern parts of Gauteng, as well as Mpumalanga,” said Saws.
There were also reports of flooding and large amounts of small hail.
The weather service reported that the isolated thunderstorm in Gauteng caused extensive damage to property and infrastructure because of the large hail.
In Mpumalanga, electrical infrastructure was impacted as a substation was affected. There were also reports of uprooted trees that fell onto power lines and fences in the Lekwa Local Municipality.
It is important to note that for the remainder of the week, partly cloudy and warm conditions will persist for most parts of the country, with hot to very hot conditions expected to be over the south-western areas of the country.
The Saws added that there will be isolated to scattered showers and thundershowers/thunderstorms, which will take place in the central and eastern parts, with no severe weather warnings issued yet.
Does the El Niño play a part?
The El Niño-Southern Oscillation (ENSO) is currently in an El Niño state, and the latest predictions say it is expected to persist through most of the summer months.
However, according to the manager of communications at Saws, Hannelee Doubell, the weather we are experiencing right now is not related to El Niño.
“This is NOT related to El Niño at all but forms part of thunderstorm activity during the early summer season,” said Doubell.
ENSO’s typical impact on Southern Africa is in favour of generally drier and warmer conditions during the summer seasons from October to March.
However, current global forecasts indicate uncertainty for the typical drier conditions that South Africa experiences during typical El Niño seasons, in particular over the eastern parts of the country.
Saws also noted that weather extremes will continue to occur from time to time during the summer season, as drier conditions are expected.
Their multi-model rainfall forecast indicates above-normal rainfall for the north-east of the country until March. So during the Nov-Dec-Jan (NDJ) period, the Dec-Jan-Feb (DJF) period, and the Jan-Feb-Mar (JFM) period, below-normal rainfall was predicted for the central and south-western parts of the country.
According to weather predictions, above-normal rainfall conditions will occur over the north-eastern parts of the country, even with an El Niño in place. However, for most of the areas where above-normal rainfall is predicted, these probabilities are low.
It is also worth noting that the El Niño effect might still manifest its influence in the next few months and change the outlook of the rainfall forecast for as late as mid- and late-summer.