Aberarth Swell Statistics, June: All Swell – Any Wind
This chart shows the variation of swells directed at Aberarth through an average June, based on 2303 NWW3 model predictions since 2006 (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 Aberarth, and at Aberarth the best grid node is 32 km away (20 miles).
The rose diagram shows the distribution of swell sizes and swell direction, 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 happened 58% of the time. Green and yellow represent increasing swell sizes and red represents biggest swells greater than >3m (>10ft). In either graph, the area of any colour is proportional to how commonly that size swell happens.
The diagram implies that the prevailing swell direction, shown by the largest spokes, was WSW, whereas the the prevailing wind blows from the W. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Aberarth and away from the coast. We lump these in with the no surf category of the bar chart. To keep it simple we don't show these in the rose plot. Because wind determines whether or not waves are clean enough to surf at Aberarth, you can load a different image that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. In a typical June, swells large enough to cause surfable waves at Aberarth run for about 11% 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.