The figure describes the range of swells directed at Little River State Beach over a normal December. It is based on 1736 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast surf and wind right at the coastline so we have chosen the best grid node based on what we know about Little River State Beach. In the case of Little River State Beach, the best grid node is 32 km away (20 miles).
The rose diagram illustrates the distribution of swell directions and swell sizes, 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 only 7% of the time. Green and yellow show increasing swell sizes and highest swells greater than >3m (>10ft) are shown in red. In each graph, the area of any colour is proportional to how often that size swell occurs.
The diagram indicates that the prevailing swell direction, shown by the largest spokes, was WNW, whereas the the dominant wind blows from the WSW. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from Little River State Beach and out to sea. We lump these in with the no surf category of the bar chart. To simplify things we don't show these in the rose plot. Because wind determines whether or not waves are clean enough to surf at Little River State Beach, 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 December, swells large enough to cause surfable waves at Little River State Beach run for about 93% 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.