Andrew Molera State Park Swell Statistics, July: 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 over a normal July and is based upon 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 largest swells greater than >3m (>10ft) are shown in red. In each graph, the area of any colour is proportional to how commonly that size swell was forecast.
The diagram implies that the prevailing swell direction, shown by the longest spokes, was W (which was the same as the most common 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 25% of the time, equivalent to 8 days. Open sea swells exceeding >3m (>10ft) are unlikely to occur in a normal July but 5% of the time we expect swell in the range 2-3m (6.5-10ft) 5%, equivalent to (2 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 think that that clean surf can be found at Andrew Molera State Park about 25% of the time and that surf is messed up by onshore wind 48% of the time. This is means that we expect 23 days with waves in a typical July, of which 8 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.