Page 1 of 1

Wind Rose Interpretation

Posted: Mon 01 Oct 2012 8:34 pm
by parksfour
Hi,
I'm a new user of weather stations, Cumulus software and forums in general.
I have been researching weather and climate and how to make sense of the data that I have been getting over the last couple of weeks. It is very interesting.
There are many questions but I am confident of mastering much of it.
The question I would like to ask now though is, how do you interpret the Wind Rose or Wind Compass?
I have looked up the topic on the net and I can find no other Wind Rose examples exactly like the one in Cumulus. I know what the compass points are but I am not sure what the length and width of the data represented means since there are no other scales like velocity or time etc.
No doubt this is a dumb question to many of you but I have been scratching my head over it for a while. No doubt I will feel like a fool when you explain it.

Re: Wind Rose Interpretation

Posted: Mon 01 Oct 2012 9:15 pm
by steve
From the help: "The third indicator gives a visual summary of the relative wind strength and direction over last few hours; the lines drawn in each direction take into account the strength of the wind as well as the length of time it has been coming from that direction."

It plots up to 3600 wind readings, depending on how long it's been running. In the case of Fine Offset stations, it reads the data every 10 seconds, so that's up to 10 hours.

Any use?

Re: Wind Rose Interpretation

Posted: Mon 01 Oct 2012 10:16 pm
by parksfour
So this is a relative indicator? It does not show the actual speed/strength of the wind but the relative speed between highest and lowest for the last 10 hours (in my case).
I noted in my earlier researching that there is software that generates graphs (?) that can show actual speed. One was from Lakes Environmental called WRPlot Viewer. This software requires wind speed data over an extended period of time.
If you are familiar with this or any other similar software can you explain how I might get the required data from Cumulus into it to generate this graph? Excel might be the means but the method defeats me.

Re: Wind Rose Interpretation

Posted: Mon 01 Oct 2012 10:32 pm
by tobyspond
Hi,

I use JPgraphs professional (paid) version to generate the windrose plots on my webpage. I upload the monthly log files to a mysql database for use in JPgraphs.

I have not looked at WRPLOT in awhile, but I think you may need to extract/copy the wind data from the monthly log file into Excel or some other similar program or you may be able to copy the data directly into WRPLOT. There is documentation and instructions on the WRPLOT site.