This image describes the range of swells directed at Westward Beach/Point Dume over a normal February. It is based on 1584 NWW3 model predictions since 2007 (values every 3 hours). The wave model does not forecast wind and surf right at the coastline so we have chosen the best grid node based on what we know about Westward Beach/Point Dume, and at Westward Beach/Point Dume the best grid node is 17 km away (11 miles).
The rose diagram describes 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 only 15% of the time. Green and yellow represent increasing swell sizes and red illustrates highest swells greater than >3m (>10ft). In each graph, the area of any colour is proportional to how frequently that size swell occurs.
The diagram suggests that the prevailing swell direction, shown by the largest spokes, was WSW, whereas the the dominant wind blows from the NNW. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Westward Beach/Point Dume and offshore. We lump these in with the no surf category of the bar chart. To avoid confusion we don't show these in the rose plot. Because wind determines whether or not waves are clean enough to surf at Westward Beach/Point Dume, you can load a different image that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. During a typical February, swells large enough to cause surfable waves at Westward Beach/Point Dume run for about 85% 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.