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How to read the weather station wind graphs
justal - 5-1-2006 at 14:35

A couple of people have asked me about some of the graphs and charts displayed within the Weather Station section and what exactly some of them show, so this is an attempt to describe some of them... I'll do one at a time. (You were right Neil, when you said we'd need instructions on how to read the data!)

The first one is the 'wind direction plot over time' graph displayed on the 'wind' page.

An example is shown here:



The first thing you need to know is the time scale over which this graph was generated. The text at the bottom right shows that it covers the last 24 hours of data, the text at the bottom left shows when it was updated (in this case 1am on the 31st). So, the graph plots the wind direction over the 24 hours previous to 1am on the 31st.

The dots in the center of the circle represent the wind directions at the beginning of this time period, the dots towards the outside of the circle represent the wind directions at the end of this time period.

We can therefore see from this example that at 1am on the 30th the wind was generally from the ESE, it then swung to the SSE for a while before backing Easterly again at around 5am. After this it swung through SE to become Southerly at around 9am before becoming SW and then predominantly WSW for much of the remaining time period.

I think that explains it??

Al.