Favourable summer rainfall conditions are mostly expected to remain in place during the next few days.
Wet conditions, with severe storms in some areas, will continue over the northeastern and eastern parts of the country until Thursday, clearing by Friday when precipitation should be confined to the far eastern parts. During the same time, wet conditions will also continue along the Garden Route and adjacent interior. Warmer, drier conditions will set in, with significant warming especially over the central parts, through the weekend.
By Sunday and early next week, another rain-bearing system will develop over the central parts of the country, with renewed development of thundershowers over the north eastern half of the country. Another cold spell may affect the southwestern parts early next week according to current forecasts.
The following is a summary of weather conditions during the next few days:
• General:
o Normal to above-normal rainfall is expected over the central to eastern summer rainfall region, including the maize-production region.
o Below-normal rainfall is expected over the western interior and winter rainfall region.
o The southern parts of the country will on average remain cooler than normal while temperatures over the northern parts will be near normal to above normal on average.
o The southern and southwestern parts of the country will be cooler than normal, with minimum temperatures in certain areas such as the Karoo and southern escarpment expected to be in the single digits during some nights and with moderate to strong winds at times.
o Thundershowers over the north-eastern to far eastern parts of the country until Thursday (14th) will have an enhanced tendency to become severe.
o There is no indication of severe cold over the summer grain production region during the coming days.
o Warm, dry and windy conditions may occur over the interior of the Northern Cape and western Free State by Sunday / Monday (17th / 18th).
o Fresh to strong southeasterlies to easterlies are expected over the southwestern parts on most days, reaching a maximum during the weekend.
• Rainfall:
o Scattered showers and thundershowers will persist over the north-eastern half of the country, including the central to eastern maize-production region, until Thursday (14th).
o Widespread thundershowers and rain, with significant falls in places, will persist over the northern to north-eastern parts of KZN until Thursday (14th).
o Rain and showers will persist along the Garden Route and adjacent interior until Saturday.
o Very little to no rain is expected during the weekend apart from isolated thundershowers mostly over the Eastern Highveld as well as some showers over the south eastern coastal parts and adjacent interior.
o Scattered to widespread thundershowers are possible over the central to eastern and north eastern parts of the country from Monday (18th).
o Light showers are possible over the southern parts of the winter rainfall region and Garden Route by Monday and Tuesday (18th / 19th).
• Temperatures:
o The southern parts will remain cool and windy through most of the period. o Most of the southern and eastern escarpment (as far north as Mpumalanga) will also remain cool until the weekend.
o It will become warm to hot over the central parts (interior of the Northern Cape, western North West and western Free State) during the weekend and early next week.
o Very hot, heat-wave conditions are possible over the Limpopo River Valley by early next week (Monday / Tuesday) according to current forecasts.
o By Sunday (17th) and Monday (18th), renewed cooling is indicated over the southwestern parts of the country as cool to cold air will invade the area from the southwest according to current forecasts. It will be windy and minimum temperatures over the southwestern and southern interior may fall to the single digits according to current forecasts.
Overview of expected conditions over South Africa during the next few days
Conditions in main agricultural production regions (13 - 19 November)
Maize production region: Widespread thundershower are expected initially over most of this region, concentrating in the east towards Thursday, with warmer and drier conditions by the weekend. On average, temperatures will be slightly near normal, especially over the western to north-western areas of the region.
Maximum temperatures over the western maize-production region will range between 27 and 33 °C (warmer conditions later in the period) while minimums will be in the order of 14 - 21°C. Maximum temperatures over the eastern maize-production region will range between 19 and 30°C (warmer conditions towards next week) while minimums will be in the order of 10 - 17°C. Isolated thundershowers are possible over the western to southern parts until Thursday (14th).
Scattered thundershowers are expected over the central to northern and eastern parts until Thursday, becoming isolated by Friday and clearing by the weekend. By Sunday isolated thundershowers will develop over the eastern parts, becoming scattered over the entire area by Monday (18th) and widespread by Tuesday (19th) according to current forecasts. Thundershowers until Thursday may become severe in some cases.
Cape Wine Lands and Ruens: It will be cool over the area on most days. Rain and showers should continue along the Garden Route until Saturday (16th). It will become warm over the Swartland and up the West Coast on Friday and during the weekend when strong to near-gale-force south easterlies are expected in the southwest. Throughout the period, the wind in the southwest will be fresh to strong south-easterly, reaching a maximum during the weekend. Over the larger part of the region, most days will be cooler than the norm for this time of the year.
Possible extreme conditions - relevant to agriculture
The South African Weather Service issues warnings for any severe weather that may develop, based on much more information (and in near-real time) than the output of one single weather model (GFS atmospheric model - Center for OceanLand-Atmosphere Studies (COLA) and Institute of Global Environment and Society (IGES) - http://Wxmaps.org) considered here in the beginning of a week-long (starting 13 November) period.
It is therefore advised to keep track of warnings that may be issued by the SAWS (www.weathersa.co.za) as the week progresses. According to current model projections (GFS model) of weather conditions during the coming week, the following may be deduced:
• Thundershowers until Thursday (14th) over the north eastern to far eastern parts may become severe (central to eastern North West, Free State, Gauteng, Mpumalanga and northern KZN).
• Daily rainfall totals may exceed 50 mm over northern KZN until Thursday (14th).
• Heat-wave conditions are expected over the Lowveld of Mpumalanga and Limpopo as well as the Limpopo River Valley on Monday / Tuesday (18th / 19th).
• Hot, dry and windy conditions over the interior of the Northern Cape and western parts of the Free State (and surrounding areas) by Sunday and Monday (17th / 18th) may be conducive to the development and spread of wild fires where vegetation is dry.
• Strong easterlies to south easterlies are possible along the southwestern coastal areas throughout the period, reaching a maximum during the weekend.
• Cool to cold and windy conditions will set in over the southwestern to southern parts on Sunday (17th), remaining in place early next week according to current forecasts. The combination of low minimum temperatures and wind may pose a threat to small stock.
