The wait for El Niño is on. Most computer forecast models continue to suggest an El Niño event will begin evolving in September and it may be a significant event for a few months during the heart of the Northern Hemisphere winter. This year already has been an interesting year for crop weather with drought still lingering in Europe, and dryness from eastern Ukraine into Russia’s Volga River Basin and in Canada’s Prairies.

On September 19, the International Research Institute for Climate and Society at Columbia University presented an update of its seasonal weather outlook, which remained somewhat unchanged from the previous month’s outlook. By this, I mean there is over 60% chance of El Niño developing over the 2018-2019 summer season. This corroborated the message shared on September 11 by the Australian Bureau of Meteorology which indicated a 50% chance of El Niño developing. 

A long-awaited shift in weather patterns is beginning to take place around the world. Drought in Europe, portions of western Russia and Canada has been slightly “eased” recently, but drought remains in each of these areas. The changes noted so far have been welcome, but drought remains in each of these areas as well as in Australia.

Thundershowers expected during the week, especially over the eastern parts where a possibility exists for storms to become severe. Dry and sunny conditions will return over the whole country by the weekend.

Important Issues:

El Nino development still in infant phase. The effect on rainfall will most probably not be typical El Nino, especially for November and December where rain is possible over the Summer Rainfall Area. Beware however for the second part of the season.

SA’s recent agricultural GDP figures, which show that the sector escaped the recession in the third quarter, expanding 6.5% on a quarter-on-quarter (seasonally-adjusted annualised) basis, are no call for celebration.

Important Issues

Short term rainfall forecasts (December) are positive but the effect of El Nino only expected in the second part of summer. Still remains a high drought risk season, especially towards the western areas.

1. Current conditions

Agricultural conditions are still on the edge of disaster in many areas. Summer crop plantings in Mpumalanga were mostly completed but in many areas also very late. Rain is needed to ensure that the crop is well established. Most of the Eastern Free State did not receive rain in time and it is estimated that less than 50% of the area is planted in time. The last recognised date for maize to emerge in this area is in the first week of December to ensure that sufficient heat units are available to complete the growing cycle.

Very little plantings were possible in the central to western summer crop production areas except for an area from Koppies, Parys and Potchefstroom to Ventersdorp where planting rain occurred. Although the planting window is still “open” until the last week of December for the western production areas, are primary cultivations not yet completed. Rain is therefore needed to first cultivate fields and then to plant, putting pressure on the time available before it is too late.

It must however be stated that in some areas are the soil water conditions in deeper layers of the soil profile relative favourable but the top layers are dry. At least 50mm to 100mm is needed in most areas to plant (central to western production areas) and eastern production areas to prevent drought damage within the next weeks.

2. El Nino and Indian Ocean
Sea surface temperatures in the Nino3.4 area (and all the other Nino-areas) exceeded the 0.5°C above average limit since the start of October. There is still however very little or no coupling with the atmosphere considering the Southern Oscillation Index (SOI) as indicator. The SOI is still in the neutral phase towards the La Nina side for the 30-day average value. Some other variables regarding El Nino are important like when the peak will be reached and will the period of be long enough to be classified as El Nino?

The Indian Ocean Dipole Index (IOD) now moved back from the positive phase to the neutral phase that is less negative for rainfall conditions over Southern Africa. It can help to soften the effect of El Nino.

3. Expected rainfall and temperature conditions
3.1 Summer Rainfall Areas
Short term forecasts indicate improved probabilities for rainfall over most of the Summer Rainfall Area for the period 7 to 10 December as well as for the last two weeks of December. The best probabilities for rain are concentrated towards the drought stricken northern and north eastern parts of the country of Gauteng, Limpopo and Mpumalanga. Good falls are also possible over most of the Free State, Northwest, Eastern Cape and KZN. Less rain is expected in the other drought stricken areas of the central to western parts of the Northern Cape and Northwest Provinces but probabilities increase for the second part of December over those two areas with lighter falls expected.

There are three scenarios in terms of the current season forward with estimated probability of occurrence:

Weaker than expected rainfall for December and January as well as last part of the summer season (February to April) when the effect of El Nino will come into play. (30% probability)
Good rainfall in December and January with very dry conditions in the last part of the season with the effect of El Nino. (50% probability)
El Nino reaction not typical. Good rainfall for rest of the season. (20% probability)
The different scenarios will also be more valid for specific geographical areas with the western areas leaning more towards Scenario 1 and the eastern areas leaning more towards Scenario 3.

3.2 Winter Rainfall Areas
Some light falls of rain still possible with cold fronts still visiting the southern tip of the country.

3.3 Namibia
Improved probabilities for rain in the second part of December but there is a high risk for drier conditions in the second part of the summer season.

4. Summary and conclusions
 Rainfall and agricultural conditions at the end of November poses reason for concern for both summer crop production and livestock grazing conditions.

Although short term rainfall forecasts are positive for rain over the Summer Rainfall Area, is good falls probably more likely over the central to northern parts of the country but weaker over the western parts.

 Uncertainty about the effect of El Nino later in the season.

Johan van den Berg Santam AGRI

More rain is expected over especially the central to southern parts during the next few days and the entire maize-production region should receive normal to above-normal rainfall.

Flash floods may occur tomorrow over the Lowveld and escarpment of Mpumalanga and above-normal rainfall is expected in the maize-production areas for the remainder of the week.

The widespread rainfall over the past two weeks has improved summer grain and oilseed crop conditions across the country. The outlook for the next couple of weeks is positive, according to a recent report from the South African Weather Service.

Precipitation over the summer rainfall region was mostly limited to the northeastern, eastern and southeastern parts during the last few days.

Drier conditions are likely to remain over the central to western Summer Rainfall Areas for the pre-winter period. Rainfall and production conditions are weaker than expected and it may be attributed to the redevelopment of El Nino that is currently taking place.

Tropical Cyclone Idai resulted in widespread heavy rain and flooding over Mozambique and Zimbabwe, reaching as far west as the central parts of Zimbabwe. The system moved out to the east again during the weekend. In South Africa, the system only caused light showers over the extreme northeastern parts.

Mostly dry conditions expected over the interior -Isolated to scattered thundershowers occurred over most of the interior during the last few days, with somewhat more widespread falls Saturday and Sunday over the Free State and southern North West.

Conditions over the interior, including the entire maize-production region, will remain favourable for rainfall during the next few days.

Once again wetter than average conditions are expected to continue over large parts, including the maize-production region. 

Today I didn’t have to stretch my head looking for a positive agricultural story to end the week with, as is sometimes the case.

1. Current conditions
The best rainfall of the season occurred in many areas in the last week of April 2019. Flooding occurred in areas like KZN, Eastern Cape, parts of the Free State and smaller areas in Gauteng and Northwest Province.

Wet field conditions in the United States are a huge concern for many producers and analysts.

The sunny and mild to warm conditions across the interior that developed late last week is set to continue for the next few days.
pixabay.com
 
AgriSeker

30 April 2019

The maize-production region will experience temperatures in the normal to above-normal range with abundant sunshine. Temperatures over the interior will increase gradually through the week until the weekend. Two frontal systems may however result in winter rainfall over the southern parts. Inclement weather may dominate the southern parts during the weekend.

According to current forecasts, cold, wet and windy conditions may spread over the Cape provinces from late Thursday, but the central to northern and eastern interior is expected to remain relatively warm, dominated by anticyclonic flow - according to current forecasts. There are early indications of the possible development of another rain-producing system by next week over the interior - the outlook is still very uncertain this far ahead.

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

• General:
o The interior is expected to by dry for the most part.
o Near-normal rainfall is expected over the winter rainfall region as well as the southern to eastern coastal belt and Eastern Cape. 
o Temperatures over the interior will on average remain in the normal to above-normal range. Over the central parts of the country, average temperatures are expected to be 2 - 6°C above the long-term mean. 
o Temperatures over the winter rainfall region will be near normal to below normal. 
o There is no indication of severe frost given the expected weather conditions during the next few days. 
o Relatively warm conditions with persistent northwesterly winds will be present over the central to northern and northwestern interior during most of the period. 
o Fresh to strong southeasterlies will occur over the southwestern parts during the weekend. 
• Rainfall: 
o No rain is expected over the interior until at least the weekend.
o Light showers are possible over the winter rainfall region on Tuesday (30th), mainly in the south. Light showers may spread along the southern to eastern coastal belt on Wednesday (1st). 
o Showers are possible over the winter rainfall region on Thursday (2nd). 
o Showers will spread along the southern and eastern coastal belt and adjacent interior on Friday (3rd) and Saturday (4th), with fresh to strong southwesterlies becoming easterly later. Light showers and drizzle will spread along the northeastern escarpment on Sunday (5th). 
o Showers or thundershowers may develop over the eastern parts (KZN, eastern Free State) by Monday (6th) while scattered showers are possible along the southern to eastern coastal belt and adjacent interior according to current outlooks. 
• Temperatures:
o Hot, berg-wind conditions are possible over the southeastern parts (mainly the eastern parts of the Eastern Cape) on Tuesday (30th) and Thursday (2nd). 
o Maximum temperatures over the western maize-production region will range between 22 and 29 °C while minimums will be in the order of 7 - 15° 
o Maximum temperatures over the eastern maize-production region will range between 21 and 27°C while minimums will be in the order of 6 - 11°C. 
o Minimum and maximum temperatures across the interior (including the maize-production region) will continue to increase gradually during the next few days. 
o It will be very hot over the Loweveld and northern KZN on Friday (3rd). 
o Cool to cold conditions with fresh southerly to southeasterly winds will invade the southern parts from Friday onwards. 
o It will be warm to hot and windy over most of the interior of the Northern Cape throughout the period, except for the southern to western parts where it will become cool to cold and windy from Friday (3rd) into the weekend. 

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

Anticyclonic circulation over the interior, with the center of the high towards the east at the surface, will result in gradual warming across most of the interior. Between the high-pressure center to the northeast and some frontal activity over the southwestern parts, a northwesterly flow will develop and is expected to persist for the most part over the interior, especially the central to western interior. The northwesterly flow across the interior may also result in hot berg-wind conditions over especially the eastern parts of the Eastern Cape on Tuesday (30th) and Thursday (2nd).

A cold front will bring isolated light showers to the winter rainfall region and Garden Route on Tuesday (30th). Another, stronger frontal system will reach the southern parts by Thursday (2nd).