Climate and agricultural conditions
- Rainfall conditions for most of the Summer Rainfall Area are likely to improve from the middle of October.
- Still hope for some rain for the Western Cape in September.
1. Current condition
Light falls of rain occurred in the second part of August 2017 over the Eastern and North-Eastern parts of the country and can be seen as the first summer rainfall. Light falls of rain also occurred over the Western and Southern Cape but it is still very far from sufficient rain to break the drought.
August 2017 was characterised by very strong and continous winds over most of the country but it can be deemed as “normal” for August. The strong wind run is a characteristic of the start of the change of seasons with cold fronts sweeping rapidly over the country.
The following are crop risks for September:
- Drought for winter grains and especially wheat in the Western Cape.
- The risk for frost and cold conditions that can damage wheat and fruit in the interior like the irrigation areas of the Northern Cape.
2. El Niño and Indian Ocean
Latest forecasts still indicate neutral or average sea surface temperatures in the Central Pacific (no El Niño) until at least the end of 2017. There is however some forecasts that favour the development of weak La Niña conditions in the second part of the summer - imitating the pattern of 2016/17.
The important Indian Ocean sea temperatures also tend towards neutral or average conditions although it is very early in the season and rapid changes can still take place
3. Expected rainfall conditions
3.1 Summer Rainfall Areas
Very little rain is expected for most of the Summer Rainfall Area for September and first part of October. Current forecasts indicate however that the conditions for rainfall will improve a lot in the second part of October (accuweather.com). At this early stage is more than 50mm likely to occur over most of the Summer Rainfall Area with the exception of the far western and north western parts of the Northern Cape.
Cold nights with frost are still possible until the middle to end of September over especially the central to southern interior.
3.2 Winter Rainfall Areas
Short to medium term forecasts still indicate some rain in the second and last week of September for the Western Cape.
Summary and conclusions
- The trend away from El Niño continues and a slight chance for La Niña conditions from midsummer can become a reality. If it is going to happen, it will follow about the same pattern as in 2016/17.
- Rainfall conditions for the Summer Rainfall Area are likely to improve from about the second part of October. Current forecasts indicate >50mm for most of the area.
- Although there are at least three rainfall events still forecasted for the Western Cape for September, is the time running out because the rainy season is nearing its end. The probability to break the drought in the next months is becoming smaller.
- The rain forecasted for September for the Western Cape may help to improve conditions for winter grains and especially the wheat crop.
- There is currently no indication of severe frost conditions for September for the interior but the general last dates for frost are only towards the end of September in the central to southern parts of the Summer Rainfall Area.