Box Beach Swell Statistics, April: All Swell – Any Wind
The graph shows the range of swells directed at Box Beach over a normal April, based on 1920 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 most applicable grid node based on what we know about Box Beach, and at Box Beach the best grid node is 34 km away (21 miles).
The rose diagram describes the distribution of swell directions and swell sizes, while the graph at the bottom shows the same thing without direction information. Five colours show increasing wave sizes. The smallest swells, less than 0.5m (1.5 feet), high are coloured blue. These were forecast only 9% of the time. Green and yellow show increasing swell sizes and red illustrates biggest swells greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how often that size swell happens.
The diagram indicates that the dominant swell direction, shown by the biggest spokes, was SE, whereas the the prevailing wind blows from the SSE. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Box Beach and offshore. We group these with the no surf category of the bar chart. To simplify things we don't show these in the rose graph. Because wind determines whether or not waves are surfable at Box Beach, you can select a similar diagram that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. During a typical April, swells large enough to cause good for surfing waves at Box Beach run for about 91% 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.