Week Two Forecast for the Period: 3 Aug 2010 to 9 Aug 2010
The high pressure system is ridging along the south coast, extending into the east coast
by tomorrow. This will result in a chance of isolated light showers over these area and
cold temperatures over the Eastern Cape interior by tomorrow. Further drop of temperatures
expected by Friday in the northern Provinces with drizzle patches along the escarpment.
From Saturday onwards no rain expected, the surface trough will dominate over the western
interior, extending down to the southern parts with a weak frontal system expected to
slip south of the country on Monday.
Second weak, no significant weather expected in the country, except some weak cold front
that will be sliping south of the country but causing a chance of isolated showers along
the coast south coast of Western Cape and Eastern Cape coast.
Maximum temperatures will remain under cool conditions but warm in KwaZulu-Natal and
cold over the south-western parts as the weak cold fornt will be brushing over these
areas.
Limitations and Use of these Products
Forecast skill drops rapidly during the first two weeks of a forecast, such that daily conditions generally become unpredictable after about a week or two. This drop in skill varies from one forecast to the next as it is based on the synoptic weather patterns prevalent during the forecast period. At the South African Weather Service we are working on improving the skill of forecasts for the second week and will in future also provide indicators of expected skill of these forecasts. For now please use these forecasts only as a guide to possible events of significance during the second week.
Temperature Distributions
These graphs show a probability distribution of the expected temperature categories during the period of the forecast. This can be used to determine the proportion of hot, warm, cool etc days during the week.
Wind Rose Graphs
Wind roses provide information on the frequency of days where the wind is expected to reach certain thresholds and also the likely direction of the wind. For example: from these graphs one can determine how many days the southeaster will blow in Cape Town and what its probable strength will be.
