Graveyards Swell Statistics, October: All Swell – Any Wind
This chart illustrates the variation of swells directed at Graveyards through a typical October. It is based on 2480 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind or surf right at the coastline so we have chosen the most applicable grid node based on what we know about Graveyards. In the case of Graveyards, the best grid node is 26 km away (16 miles).
The rose diagram shows the distribution of swell sizes and directions, while the graph at the bottom shows the same thing but without 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 4% of the time. Green and yellow show increasing swell sizes and red represents largest swells greater than >3m (>10ft). In either graph, the area of any colour is proportional to how commonly that size swell was forecast.
The diagram implies that the prevailing swell direction, shown by the longest spokes, was SW, whereas the the most common wind blows from the SSW. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from Graveyards and out to sea. 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 diagram. Because wind determines whether or not waves are clean enough to surf at Graveyards, you can select a similar diagram that shows only the swells that were expected to coincide with glassy or offshore wind conditions. Over an average October, swells large enough to cause surfable waves at Graveyards run for about 96% 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.