Aberwystwyth Beach Swell Statistics, November: All Swell – Any Wind
The figure illustrates the variation of swells directed at Aberwystwyth Beach through an average November, based on 2386 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind and surf right at the shore so we have chosen the most applicable grid node based on what we know about Aberwystwyth Beach. In the case of Aberwystwyth Beach, the best grid node is 29 km away (18 miles).
The rose diagram shows the distribution of swell directions and swell sizes, while the graph at the bottom shows the same thing but without direction information. Five colours illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. These occurred 42% of the time. Green and yellow illustrate increasing swell sizes and red illustrates the largest 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 most common swell direction, shown by the biggest spokes, was SW, whereas the the most common wind blows from the WSW. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Aberwystwyth Beach and away from the coast. We lump these in with the no surf category of the bar chart. To avoid confusion we don't show these in the rose diagram. Because wind determines whether or not waves are good for surfing at Aberwystwyth Beach, 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 November, swells large enough to cause clean enough to surf waves at Aberwystwyth Beach run for about 36% 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.