The next few days are expected to be somewhat cooler than the norm for this time of the year over the southern to eastern parts of the country, where easterly to south easterly winds will advect moisture for most of the days with substantial cloud cover at times.
Warm and dry conditions will persist over the north western parts (mainly northern half of the Northern Cape and adjacent areas) according to current forecasts. The generally favourable rainfall situation over the interior will also be associated with strong south easterlies in the southwest. Rain-bearing systems (cut-off lows) over the southern parts may also be associated with heavy downpours at times and possible severe storms in places.
The following is a summary of weather conditions during the next few days:
• General:
o The period will be relatively cool over the southern to eastern parts with above-normal rainfall.
o The winter rainfall region is also expected to receive rain
o The northern half of the Northern Cape and adjacent areas are expected to remain mostly dry. o It will be very windy over the southern parts of the country at times.
o It will generally be windy for this time of the year over most of the interior, especially the central to southern parts and from time to time also over the Highveld.
o Strong south easterlies are possible over the southwestern parts for most of the period.
• Rainfall:
o Scattered showers and thundershowers are expected on most days over the central to eastern summer rainfall region, including the entire maize-production region except for the extreme southwestern parts.
o Widespread rain and thundershowers are possible over Limpopo and central to eastern Mpumalanga during the weekend. Heavy falls are possible along the escarpment and the Lowveld.
o Scattered rain and thundershowers are expected over the Western Cape, Eastern Cape and southern parts of the Northern Cape during the weekend and possibly again by Wednesday (22nd). Heavy falls are possible over the mountainous areas in the Western Cape.
o Except for isolated thundershowers at times, the northern half of the Northern Cape should remain dry for the most part according to current forecasts.
• Temperatures:
o It will be cool to cold over the southern parts, with maximum temperatures below 20°C, accompanied by strong winds which should lower the sensible temperature, during the weekend and into early next week as well as possibly by Wednesday and Thursday (22nd and 23rd).
o Mild conditions will dominate over the interior and along the coast for the most part. Maximum temperatures over the interior will remain below the lower 30s for the most part.
Overview of expected conditions over South Africa during the next few days
A tropical low-pressure system in the north, moving across Zimbabwe, together with an upper-air low over Botswana will initially bring widespread rain and thundershowers to the north eastern parts. Two upper-air cut-off lows developing over the southwestern parts during the period will also result in widespread thundershowers over the interior, together with rain and thundershowers over the southern parts, including the winter rainfall region. Conditions in main agricultural production regions (17 - 22 January)
Maize production region:
It will be cooler than normal for most of the period. Isolated to scattered showers and thundershowers are expected on most days. Maximum temperatures over the western maize-production region will range between 24 and 30 °C. Minimums will be in the order of 14 - 19°C. Maximum temperatures over the eastern maize production region will range between 22 and 29°C while minimums will be in the order of 10 - 15°C.
Cape Wine Lands and Ruens:
Widespread rain and thundershowers are expected, especially during the weekend and again by Wednesday (22nd). The wind will be strong southerly to south easterly, especially in the southwest, especially during the weekend and again by the 22nd. Temperatures will be below normal for this time of the year.
Possible extreme conditions - relevant to agriculture
According to current model projections (GFS model) of weather conditions during the coming week, the following may be deduced:
• Rain and thundershowers over the north eastern parts may result in heavy falls over the north eastern escarpment and Lowveld during the weekend.
• Showers or thundershowers during the weekend over the mountainous regions of the Western Cape may be associated with heavy downpours and could possibly lead to localised flooding.
• Thundershowers during the weekend and next week over the mountainous regions of the Western Cape may have a tendency to become severe, with hail.
• Cool, wet and windy conditions over the southern parts of the country for extended periods may have a negative impact on small stock.
• Some thundershowers over the central parts of the country by next week may have a tendency to become severe.
