This image shows only the swells directed at Fernandina Beach Pier that coincided with light winds or offshore conditions through a typical September. It is based on 1680 predictions, one every 3 hours. The direction of the spokes show where quality surf generating swell comes from. Five colours show increasing wave sizes. The smallest swells, less than 0.5m (1.5 feet), high are coloured blue. Green and yellow represent 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 happens.
The diagram indicates that the prevailing swell direction, shown by the largest spokes, was E, whereas the the dominant wind blows from the E. The chart at the bottom shows the same thing but without direction information. For example, swells larger than 1.5 feet (0.5m) coincided with good wind conditions 12% of the time, equivalent to 4 days. Open sea swells exceeding >3m (>10ft) are unlikely to arise in a normal September. Taking into account the fraction of these swells that coincided with expected offshore winds, and given the fact that Fernandina Beach Pier is exposed to open water swells, we estimate that clean surf can be found at Fernandina Beach Pier about 12% of the time and that surf is messed up by onshore wind 52% of the time. This is means that we expect 19 days with waves in a typical September, of which 4 days should be surfable.
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.