Vaisala Xweather Energy

Vaisala Energy Support

How do I interpret the wind rose provided by the Annual Mean Wind Rose Tool?

The wind rose indicates the frequency with which the wind blows from a given direction (N - North, S - South, E - East, W - West). Wind roses provided by 3TIER’s Wind Prospecting Tools are an annual average (mean). The length of each wedge indicates the frequency, with the distance between two concentric circles representing a frequency of 10%. For example, a wedge directed straight up (N) and extending 3 rings means that the wind blows from the North 30% of the time. Directional bins are 45 degrees wide.

Please note that each annual wind rose scales to your selected location, meaning some wind roses will have more rings than others. Generally the more often wind blows in a certain direction, the more rings your wind rose will have. For example, the wind rose for an area with a frequency of 10% would have one ring, where as an area with a 50% frequency would have five rings.

If you didn't find what you were looking for, please contact 3TIER Support for additional assistance.