Andrew Molera State Park Swell Statistics, August: Surf with Light or Offshore Winds
This image shows only the swells directed at Andrew Molera State Park that coincided with light winds or offshore conditions through a typical August. It is based on 2480 predictions, one every 3 hours. The direction of the spokes show where quality surf generating swell comes from. Five colours illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. Green and yellow illustrate increasing swell sizes and red illustrates the biggest swells, greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how frequently that size swell happens.
The diagram suggests that the prevailing swell direction, shown by the largest spokes, was WNW (which was the same as the prevailing 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 26% of the time, equivalent to 8 days. Open sea swells exceeding >3m (>10ft) are unlikely to arise in a normal August but 15% of the time you can expect swell in the range 1.3-2m (4-6.5ft) 15%, equivalent to (5 days). Taking into account the fraction of these swells that coincided with predicted offshore winds, and given the fact that Andrew Molera State Park is exposed to open water swells, we calculate that clean surf can be found at Andrew Molera State Park about 26% of the time and that surf is blown out by onshore wind 43% of the time. This is means that we expect 21 days with waves in a typical August, 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.