How is the direction data aggregated, especially when the wind is out of the north?
For charts of two or more days, I don’t have a great way to aggregate near-North direction data (that is, directions that are bouncing back and forth between slightly greater than 0 and slightly less than 360). So I simply use the average of the 4 direction readings. This method can produce an erroneous result of approximately 180 (or 20 using Waconia direction notation) if the direction is near North (example: (3 + 359 + 2 + 358)/ 4 = 180.5). In the one-day charts this is not an issue because there is no aggregation of the HMS 15-minute data.
