Cumulus Report: 31 January 2019 South Africa .

Star InactiveStar InactiveStar InactiveStar InactiveStar Inactive
 

After large parts of South Africa experienced a drought in January, the central parts of the country are expected to receive wide-spread thundershowers over the weekend, especially the Free State and Northwest.

 
Recent observations and climate model outlooks suggest the immediate risk of El Niño has passed but there remains an increased likelihood that it will develop later in 2019, according to the latest Cumulus report.

Following hot and dry conditions during the middle part of January, which can be seen as a mid-summer drought in many areas, scattered to widespread showers and thundershowers started to occur from 24 January over the eastern and north eastern parts of the country. Some areas received significant daily totals. Some thundershowers became severe. Rainfall was mostly confined to the northern and eastern parts of the country - as far west as the northern parts of the Free State and central parts of North West. The western maize-production region still hasn't received any significant rainfall since the early part of the month.

The favoured area for rainfall will shift towards the central parts of the country during the next few days. The persistent hot, dry and windy conditions will be replaced with partly cloudy to cloudy conditions with temperatures closer to the near-normal range. At first, the distribution of thundershowers will be in the isolated to scattered category. However, by the weekend, widespread thundershowers are expected especially over the Free State and North West.

The upper-air system responsible for an intensification of rainfall over the summer rainfall region may also result in thundershowers over large parts of the winter rainfall region on Saturday, 2 February. The north eastern parts of the country will be somewhat drier during the next few days.

The wetter conditions over large parts of the summer rainfall region will be associated with frequent ridging of the Atlantic Ocean Anticyclone resulting in strong south easterlies expected over the south western parts of the winter rainfall region on several days.

Conditions in the main agricultural production regions: 29 January - 4 February
In the maize production region scattered thundershowers are expected for the entire region on most days during the next week. Falls may be particularly wide spread on Friday and Saturday (1 and 2 February). On Sunday, widespread thundershowers are still possible, clearing from the west. There may be an increased tendency for storms to become severe on this day as clearance takes place from the west, with storms mostly confined to the northern and eastern parts of the region by Monday. During this entire period, temperatures will be in the mild category, with some warming indicated towards next week over the western parts when the wet conditions may contract north-eastwards.

In the Cape Wine Lands and Ruens moderate to strong south easterlies will continue to dominate during the week, especially over the south western parts. This may lead to a continuation of high-fire danger conditions. Hot conditions will occur over the Karoo on Tuesday and Wednesday. As the wind direction becomes somewhat more easterly over the region, hot conditions will focus on the West Coast, Swartland and Boland by Friday and Saturday (1 and 2 February). An upper-air low may deepen over the area by Saturday, leading to scattered thundershowers over most of the interior and in places also along the coast. These storms may produce significant totals in isolated areas over the Boland and into the Karoo as well as the interior part of the Garden Route. This type of weather system development has in the past also been associated with an increased possibility of hail storms over the interior, over places such as the Ceres Valley. Winds may become more southerly to south westerly by Sunday with mild and dry conditions over the entire area.