For January, rainfall over almost the entire summer rainfall region was above normal. A significant portion of the total rainfall was contributed directly or indirectly by Tropical Cyclone Eloise towards the end of the month. Again, as seen during November and December, it was especially the central parts of the country where above-normal rainfall dominated. This area includes the western maize-production region. Current forecasts indicate a continuation of wet conditions over the central to northeastern parts, including the entire dryland maize-production region. While generally very much supportive of crop production, cumulative rainfall totals in some areas may further increase the likelihood or extent of flooding while the persistent wet conditions may result in the occurrence of fungal pathogens. Towards and during the weekend, the area of main rainfall activity is expected to shift somewhat northeastwards.
The continued presence of a tropical low pressure system over northern Botswana and Namibia will play an important role, together with favorable upper-air conditions and a surface on-shore flow from the east. These components will yield abovenormal rain over the central to northeastern summer rainfall region, coupled with near-normal to below-normal temperatures, with extensive cloud cover keeping maximum temperatures on the low side. The following is a summary of weather conditions during the next few days:
• General: The central to northeastern parts will be cooler and wetter than normal while the western to southwestern parts of the country will be warmer and drier than normal.
Most of the summer rainfall region should receive above-normal rainfall except for the summer rainfall regions of the Cape Provinces and southern KZN. o Cumulative rainfall totals over the next week will likely exceed 50 mm over the entire summer-grain production area, with totals over parts of North West expected to exceed 100 mm.
The area of widespread precipitation is expected to contract northwards and northeastwards as the week progresses, with drier conditions expanding from the west into the Free State and western to central North West by the weekend according to current forecasts. o The western interior should be warm and dry for the most part, becoming hot towards the weekend while the area of warm and dry conditions should expand somewhat eastwards.
Persistent cloudy and wet conditions over much of the summer-grain-production region may result in the development of fungal pathogens. o Temperatures over the main summer-grain production region will generally be supportive of crop production, but somewhat on the low side with regards to maximum temperatures in the east:
▪ Maximum temperatures over the western maize production areas will be in the order of 19 – 30°C, with cooler, cloudy conditions concentrated towards the beginning of the period. Minimum temperatures will be in the order of 15 – 20°C. ▪ Maximum temperatures over the eastern maize-production region will range between 12 and 26°C, with highest values later this week according to current forecasts, followed by lower temperatures early next week. Minimums will be in the order of 10 – 17°C.
Detailed: Tuesday (2 nd): Cloudy, cool and windy over the central to northeastern half of the country. Widespread rain and showers are possible over the North West, Free State, Gauteng, southern Mpumalanga and western KZN. Totals over North West and the northern Free State and surrounding areas may exceed 50 mm. It will be mostly sunny and warm over the southwestern parts, with isolated thundershowers possible as far west as the central parts of the Northern Cape.
Wednesday (3 rd): The wind over the northeastern parts will calm down while it will also be somewhat warmer. It will remain cloudy to overcast with rain initially over the North West, Free State and western KZN, clearing during the day.
Thursday to Saturday (4 th –6 th): Partly cloudy to cloudy and mild to warm over the northeastern half of the country with scattered thundershowers. The southwestern parts will be warm and dry. It will be hot over the interiors of the Cape provinces. o Sunday (7 th): Precipitation will generally contract and focus somewhat further northwards while it should be warmer and drier over much of the Free State and central to western North West.
It will be partly cloudy to cloudy with isolated thundershowers over the northeastern parts, but scattered over the western parts of Limpopo and the surrounding areas. Scattered thundershowers are also possible over the eastern half of the Eastern Cape into KZN. It will become cloudy and cooler with light showers along the Garden Route, spreading eastwards towards the coast of KZN. o Monday (8th): It will be mostly warm and dry, but isolated thundershowers are expected to continue in the northeast and east. The coast and adjacent interior of the Eastern Cape and KZN should see some additional light showers.
Typical patterns during similar summers are: • Late September – 20 October: Relatively wet conditions over the summer rainfall region • Late October – 20 November: Mostly drier than normal conditions • Late November - December: Near-normal rainfall over the summer rainfall region • January – late February: Normal to above-normal rainfall over the summer rainfall region • Late February – March: Mostly drier than normal.
Overview of expected conditions over South Africa during the next few days
The ridging of the Atlantic Ocean Anticyclone around the country, feeding moisture from the east into the interior, together with the persistence of the tropical low pressure system over Botswana, will keep conditions very favorable for widespread summer rainfall over the central to northeastern parts during the period. An upper-air trough moving slowly northeastwards during the period will drag favorable conditions northeastwards as the week progresses. The system will initially support rainfall over especially North West and the Free State.
Towards ad during the weekend, it will support precipitation mostly over the areas surrounding the western parts of Limpopo, according to current forecasts. Conditions in main agricultural production regions (2 - 8 February) Maize production region: It will be cloudy to overcast and cool initially with widespread rain and showers, especially over the western parts, until Wednesday (3rd). During the rest of the week, partly cloudy to cloudy and mild conditions will dominate with scattered thundershowers. Thundershowers should become more isolated in nature and concentrate more towards the north during the weekend when it should clear over the southwestern parts and become warmer.
Temperatures over the entire region will be normal to below normal, with daytime temperatures suppressed by extensive cloud cover. Cool conditions will dominate in the west especially during the early part of the period. Maximum temperatures in the east may be on the low side with respect to grain production. Maximum temperatures over the western maize production areas will be in the order of 19 – 30°C, with cooler, cloudy conditions concentrated towards the beginning of the period. Minimum temperatures will be in the order of 15 – 20°C. Maximum temperatures over the eastern maize-production region will range between 12 and 26°C, with highest values later this week according to current forecasts. Minimums will be in the order of 10 – 17°C. Cape Wine Lands and Ruens:
The period will be characterized by southerly to south-easterly winds, keeping the garden route relatively cool while the Swartland, West Coast, Karoo and Boland will be warm to hot on most days. Light showers are possible mostly along the Garden Route on Thursday (4th) and Saturday (6th). The wind in the southwest will be moderate to fresh southerly to southeasterly most of the time.
