This image shows only the swells directed at Manresa State Beach that coincided with light winds or offshore conditions over a normal November and is based upon 1680 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 represent increasing swell sizes and red represents the largest 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 largest spokes, was WNW, whereas the the most common wind blows from the N. 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 53% of the time, equivalent to 16 days. Open water swells exceeding >3m (>10ft) only occur 4% of the time in a typical November, equivalent to just one day but 32% of the time we expect swell in the range 2-3m (6.5-10ft) 32%, equivalent to (10 days). Taking into account the ratio of these swells that coincided with predicted offshore winds, and given the fact that Manresa State Beach is exposed to open water swells, we estimate that clean surf can be found at Manresa State Beach about 53% of the time and that surf is spoilt by onshore wind 44% of the time. This is means that we expect 29 days with waves in a typical November, of which 16 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.