SABI Magazine Volume 9 Issue 3 | Page 42

Weather

Weather - Seasonal Climate Watch

February to June 2017

Advisory
Most of the local and international forecasting systems consistently indicate that South Africa ’ s summer-rainfall areas may expect wetter conditions during the latter parts of the summer season ( FMA ). The likelihood , slightly favouring wetter conditions , however remains relatively low .
Temperatures are expected to be warmer than normal across the country , though similar to the rainfall outlook there is a significant amount of uncertainty in the forecast .
Recommendation
Even though some relief of the severe drought conditions has occurred over the eastern and north eastern parts of the country the central and western parts of the country are still burdened with below normal rainfall conditions . The public is reminded that with winter on the horizon significant water loss can be expected with the
usual decline of rainfall as well as high amounts of evaporation , particularly over the summer rainfall areas . Thus water saving measures to continue are highly recommended across the country . As usual , it is also very important to keep monitoring any developments that may provide more clarity on the current expectations for the coming seasons .
Rainfall
The forecasting system shows chances for above-normal rainfall conditions for most of the country the coming season , but with a relatively low probability ( see Figure 1 ). It is worth noting however that even though wetter conditions are expected throughout the autumn season , the climatological rainfall tends to dramatically decrease over the northeastern parts of the country during autumn .
Minimum and Maximum Temperatures
Forecasts show a tendency of above-normal temperatures with an increasing uncertainty ( see Figure 2 ). Similar to the rainfall noted above climatological temperatures drop towards winter across the country and the expected conditions should be used accordingly .
Figure 2 : Probabilistic minimum ( left panel ) and maximum ( right panel ) temperature forecasts for the three overlapping seasons valid for the period of February to June 2017 . Forecast quality for average seasonal temperature is indicated in the Appendix ( Figure A2 )
Figure 1 : Rainfall forecasts for the three overlapping seasons valid for the period of February to June 2017 and extreme forecasts for February to April 2017 season ( right panel ). Forecast quality for total seasonal rainfall is indicated in the Appendix ( Figure A1 ).
Information supplied by South African Weather Service .
For more information please contact : Cobus Olivier - Scientist : Prediction Research : cobus . olivier @ weathersa . co . za Website : www . weathersa . co . za Weatherlines : 012 367 6000 and USSD - * 120 * 7297 #
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SABI | FEBRUARY / MARCH 2017