CO ME RA IN , CO ME SHIN E
Percentage of normal rainfall for season (July 2015 - March 2016)
(Based on preliminary data, normal period 1981-2010)
•••
THE COURSE of the 2015/16 season in
South Africa is reflected in the map on the
left. The April rainfall report by the South
African Weather Service was not available at
the time of writing this article. The area in
the central part of South Africa where below
average rain was received, is clearly visible. The
area in the central part of South Africa where
below average rain was received reduced in size
since January due to good rainfall over parts of
the Eastern Free State and Mpumalanga. Parts
of Mpumalanga received even more rain than
the long-term average. During a visit to the
province it became evident that good yields
are expected.
PROSPECTS FOR THE 2016/2017 SEASON:
The sea temperatures over the Niño3-4 area in
the Pacific Ocean are decreasing. The variances
in the average sea temperature were the highest
in recorded history. Such warm sea temperatures
usually have catastrophic climatological consequences in other parts of the world, such as
South Africa.
The International Institute of the University
of Columbia indicates the predicted La Niña-epi
sode for the coming season in the graph below.
The chances of a La Niña-type season are fairly
good according to the different prediction models.
Graph 1. Comparison between the 1991/92 and the 2015/16
seasons and the long-term rainfall of the traditional Senwes
area.
THE 1991/92 season was the worst season over the
past 40 years as far as crop performance is concerned.
The season was an El Niño-type season. Comparisons
were made between this season and the 1991/92 season. The difference between die two seasons is that the
1991/92 season started well but ended in a disaster.
The current season did not start well but ended somewhat better. A very dry February was a deathblow
to maize production in various districts. Most of the
maize pollinated during February due to the late plantings and the below average rainfall during February
took a heavy toll.
The graph above reflects the difference in rainfall
distribution in 1991/92 and 2015/16 against the longterm average rainfall trend.
SUMMARY AND CONCLUSION
A large variation in rainfall was experienced
during the past season. Large parts of the western maize production area got the worst of it.
Most international weather forecast services indicate that the chances of a La Niña-type season
are fairly good. A La Niña-type season usually
results in normal to above normal rainfall for
the season. We trust that this forecast will ring
true.
SENWES Scenario • JUN/JUL 2016
41