Average wind Cumulus NOAA annual vs Weatherlink

[grandrouge]

Hi

Can anyone explain why today I found that the wind average here is two different values.

Cumulus NOAA annual report 2012 to date has average wind at 12.6mk/hr

The same report in Weatherlink gives 6.2km/hr.

My weather software is only downloaded every couple of days and the software does not remain on even when I am working on my computer hence the values are crated only from downloaded data form my Vantage Vue.

I know I live in an exposed area and had even contemplated a wind turbine yet the Weatherlink figures discouraged me. Today I see the Cumulus figure and it might be time to start re looking at this idea.

Thanks

[steve]

I suspect that your Cumulus figure is skewed because you only use logger data. Cumulus calculates the average wind speed for the NOAA report by trawling through the monthly logs, summing the values for the current wind speed (the sixth item in each entry), and dividing by the number of entries. It therefore assumes that each entry has equal 'weight', i.e. each one covers the same period. In your case this is probably true. However...

When using the data from the logger, the logger entry contains the high wind speed for the period covered by the logger entry, and it is this value which Cumulus uses for 'current' wind speed (so as not to miss any peak values). So in your case, your 'current' values are all short-term high values, and hence the average calculated for the NOAA report may be on the high side. Weatherlink will have its own way of calculating the average, and as it was written specifically for a Davis station and for no other station, it may well use items of data supplied by the station which Cumulus (being general purpose, multi-station software) does not.