Pleasant autumn weather is set to continue over most areas, but conditions will be more favorable for rainfall over parts of the interior compared to the previous week.
There is still no indication of an outbreak of early cold events and early frost over the interior - good news for maize production especially where planting happened somewhat late. The interior will be somewhat warmer than the norm on average for this time of the year. Rainfall should, for the most part, concentrate in a northwest - southeast diagonal band across the country, mostly across the northern parts but excluding the northern parts of Limpopo. The maize-production region, especially Mpumalanga, should receive above-normal rainfall.
The following is a summary of weather conditions during the next few days:
• General:
o The maize-production region should receive above-normal rainfall for the most part.
o The southwestern interior as well as most of Limpopo is expected to remain dry for the most part according to current forecasts.
o Temperatures across the interior should be near normal to above normal for the most part.
o The earlier part of the period will see relatively high temperatures, but cooling is expected especially over the southern, central and eastern parts where especially maximum temperatures will trend downwards.
o The winter rainfall region as well as most of the coast and adjacent interior should be cooler than the norm for this time of the year.
o Very little rain is expected over the winter rainfall region.
o Cold fronts will influence the winter rainfall region and southwestern to southern interior during the period. Rainfall associated with these should be light. Three systems are expected to influence these areas during the period according to current forecasts.
o Strong southeasterlies are expected in the southwest on Wednesday (25th) and Thursday (26th) and possibly again by early next week.
• Rainfall:
o Light showers are expected over the winter rainfall region and along the Garden Route on Wednesday (25th) as a cold front moves across the area.
o Showers will move up the southern to eastern coastal belt and adjacent interior on Thursday (26th).
o Scattered thundershowers will develop over the maize-production region on Friday (27th).
o Isolated to scattered thundershowers will occur over the central to southeastern parts and Highveld on most days from Saturday (28th) until early next week, spreading into the Northern Cape early next week.
o Cold fronts may result in light showers over the winter rainfall region on Saturday (28th) and Monday night (30th) according to current forecasts.
• Temperatures:
o It will be hot over the Lowveld on Thursday (26th).
o Cooler air will invade the country from the south and bring lower temperatures, with minimum temperatures in the single digits, to the southern parts on Thursday (25th).
o Cooler air will invade the eastern to central parts from the east on Friday (27th).
o It will be cloudy with low maximum temperatures over Mpumalanga and adjacent interior on Friday (27th).
o It will be warm and windy over the central to western interior on |Saturday (28th) and Monday (30th).
o It will be very hot over the western to southern parts by early next week according to current forecasts.
o Maximum temperatures over the western maize-production region will range between 23 and 30°C with lower temperatures towards the end of the period. Minimums will be in the order of 15 - 20°C.
o Maximum temperatures over the eastern maize-production region will range between 14 and 28°C with lowest temperatures on Friday (27th) while minimums will be in the order of 11 - 15°C.
Overview of expected conditions over South Africa during the next few days
Cold fronts will influence the southwestern parts of the country during this period. A strong ridging high pressure system coupled with a developing upper-air trough over the interior will bring cloudy and cool conditions over the eastern parts on Friday (27th) with widespread showers and thundershowers over the Highveld, focusing on Mpumalanga and the adjacent parts of the surrounding provinces. Associated with more cold fronts in the south, another upper-air trough will develop over the western parts early next week and enhance the probability for thundershowers over the central areas.
Conditions in main agricultural production regions (25 - 31 March)
Maize production region:
The regions should receive above-normal rainfall during this period, mostly in the form of thundershowers from Saturday (28th) onwards. The central to eastern parts should be cloudy and cool to cold on Friday 927th) with rain and thundershowers. Maximum temperatures over the western maize-production region will range between 23 and 30°C with lower temperatures towards the end of the period. Minimums will be in the order of 15 - 20°C. Maximum temperatures over the eastern maize-production region will range between 14 and 28°C with lowest temperatures on Friday (27th) while minimums will be in the order of 11 - 15°C.
Cape Wine Lands and Ruens:
It will be somewhat cooler than normal over this region. Three frontal systems will bring light showers to the region on Wednesday (25th), Saturday (28th) and late Monday (30th) according to current forecasts. These events will be associated with the normal cloudy, windy and wet spells as is often seen when cold fronts brush the area. Rainfall totals should for the most part be low.
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:
• Hot conditions are possible over the Lowveld on Thursday (26th).
• It will be cool to cold (and windy in some places) over the southern interior by Friday morning. The cold conditions may adversely affect small stock in the region.
• Some thundershowers over eastern North West, Gauteng and Mpumalanga on Friday (27th) may become severe.
• Some thundershowers over the central parts by Tuesday (31st) may become severe.
• Strong southeasterlies are expected over the southwestern parts by Wednesday (25th) and Thursday (26th) and again by early next week. Where vegetation is dry this may lead to the development and spread of wild fires.
