Cumulus Report: 24 January 2020

Star InactiveStar InactiveStar InactiveStar InactiveStar Inactive
 

Widespread rain and thundershowers are possible over the central to northeastern parts especially during the rest of the week and into the weekend.

Following the rainfall event, mostly dry conditions may occur from early next week. Also, a frontal system will bring widespread rain and showers to the Western Cape during the weekend whilst causing an influx of dry air into the interior by next week. Temperatures will on average be near normal.

The following is a summary of weather conditions during the next few days:

• General:

o Over the summer rainfall region, the Highveld is expected to receive above-normal rainfall
o The entire maize-production region should receive rain.
o The winter rainfall region is also expected to receive rain
o The Northern Cape is expected to remain mostly dry.
o A cold front will bring colder, windy conditions to the southern half of the country from Sunday (26th) to Tuesday (28th).
o It will generally be windy for this time of the year over the central to southern parts.
o Strong south easterlies are possible over the southwestern parts in the beginning of the period.

• Rainfall:

o Scattered rain and thundershowers will set in over the northeastern provinces, focusing on the North West and surrounding areas, on Thursday (23rd) and Friday (24th), clearing during Saturday (25th).
o Scattered thundershowers are also possible over the Karoo on Friday (24th).
o Isolated thundershowers are possible over the northeastern parts into early next week.
o Rain and showers with windy conditions and lower temperatures are possible over the winter rainfall region and Garden Route as well as the Karoo on Sunday (26th) and Monday (27th).
o Light showers will move along the coast into northern KZN on Monday.
o Dry conditions will spread over the interior except the northeastern parts from Monday (27th).
o Little to no rain is expected over the Northern Cape.

• Temperatures:

o On average, temperatures over the country will be near normal.
o Cool to cold and windy conditions will spread over the southern parts with minimum temperatures in the single digits in some areas from Sunday (26th) to Tuesday (28th).
o Hot conditions will develop over the western parts of the country and along the West Coast by early next week.

Overview of expected conditions over South Africa during the next few days

An upper-air cut-off low developing over the southwestern parts will bring widespread rain and thundershowers to the central to northeastern parts initially. This will clear by late Saturday while isolated to scattered thundershowers will still move over the central to eastern parts by Sunday (26th). A cold front will invade the southwestern areas by Saturday night / Sunday morning, bringing rain to the winter rainfall region and Garden Route, while spreading dry air into the interior, resulting in little to no rain over most parts during next week.

Conditions in main agricultural production regions (23 - 29 January)

Maize production region:

Widespread rain and thundershowers are possible until Saturday over much of the region, with extensive cloud cover. It will clear over most parts by early next week except for isolated thundershowers still possible over the eastern parts. Maximum temperatures over the western maize-production region will range between 25 and 31 °C. Minimums will be in the order of 13 - 18°C. Maximum temperatures over the eastern maize-production region will range between 23 and 29°C while minimums will be in the order of 11 - 15°C.

Cape Wine Lands and Rûens:

While mostly mild, a cold front will bring colder conditions with rain during the weekend over most areas. It will be warm to hot along the West Coast and northern interior by early next week. Strong south easterlies are expected only by the middle of next week over the southwestern parts.

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:

• Cool, wet and windy conditions over the southern parts of the country from Saturday (25th) into early next week may have a negative impact on small stock.
• Some thundershowers over the central parts of the country on Friday (24th) and Saturday (25th) and over the eastern parts on Sunday (26th) may have a tendency to become severe with strong winds and damaging hail.
• It will very hot over the western interior and West Coast early next week.