Trial Harbour Swell Statistics, February: All Swell – Any Wind
The rose diagram shows the variation of swells directed at Trial Harbour through a typical February and is based upon 2102 NWW3 model predictions since 2007 (values every 3 hours). The wave model does not forecast wind or surf right at the coast so we have chosen the best grid node based on what we know about Trial Harbour. In this particular case the best grid node is 16 km away (10 miles).
The rose diagram shows the distribution of swell directions and swell sizes, while the graph at the bottom shows the same thing but lacks direction information. Five colours represent increasing wave sizes. Very small swells of less than 0.5m (1.5 feet) high are shown in blue. These were forecast only 0% of the time. Green and yellow show increasing swell sizes and red represents biggest swells greater than >3m (>10ft). In either graph, the area of any colour is proportional to how often that size swell happens.
The diagram indicates that the prevailing swell direction, shown by the biggest spokes, was SW, whereas the the prevailing wind blows from the S. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Trial Harbour and offshore. We group these with the no surf category of the bar chart. To avoid confusion we don't show these in the rose graph. Because wind determines whether or not waves are surfable at Trial Harbour, you can load a different image that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. Over an average February, swells large enough to cause good for surfing waves at Trial Harbour run for about 100% of the time.
IMPORTANT: Beta version feature! Swell heights are open water values from NWW3. There is no attempt to model near-shore effects. Coastal wave heights will generally be less, especially if the break does not have unobstructed exposure to the open ocean.