Airport Lefts Swell Statistics, March: Surf with Light or Offshore Winds
This image shows only the swells directed at Airport Lefts that coincided with light winds or offshore conditions over a normal March. It is based on 2220 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 illustrate increasing swell sizes and red illustrates the highest swells, greater than >3m (>10ft). In either graph, the area of any colour is proportional to how often that size swell happens.
The diagram indicates that the dominant swell direction, shown by the biggest spokes, was SW (which was the same as the dominant wind direction). 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 56% of the time, equivalent to 17 days. Open sea swells exceeding >3m (>10ft) are unlikely to arise in a normal March but 10% of the time we expect swell in the range 2-3m (6.5-10ft) 10%, equivalent to (3 days). Taking into account the proportion of these swells that coincided with expected offshore winds, and given the fact that Airport Lefts is exposed to open water swells, we calculate that clean surf can be found at Airport Lefts about 56% of the time and that surf is blown out by onshore wind 44% of the time. This is means that we expect 31 days with waves in a typical March, of which 17 days should be clean enough to surf.
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.