Atlantic Terrace Swell Statistics, April: Surf with Light or Offshore Winds
This image shows only the swells directed at Atlantic Terrace that coincided with light winds or offshore conditions through a typical April and is based upon 2160 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 show increasing swell sizes and red represents the biggest swells, greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how commonly that size swell was forecast.
The diagram implies that the dominant swell direction, shown by the biggest spokes, was SSE, whereas the the prevailing wind blows from the WSW. 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 25% of the time, equivalent to 8 days. Open sea swells exceeding >3m (>10ft) are unlikely to occur in a normal April but 6% of the time you can expect swell in the range 1.3-2m (4-6.5ft) 6%, equivalent to (2 days). Taking into account the proportion of these swells that coincided with predicted offshore winds, and given the fact that Atlantic Terrace is exposed to open water swells, we estimate that clean surf can be found at Atlantic Terrace about 25% of the time and that surf is blown out by onshore wind 45% of the time. This is means that we expect 21 days with waves in a typical April, of which 8 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.