The Pass Swell Statistics, December: Surf with Light or Offshore Winds
This image shows only the swells directed at The Pass that coincided with light winds or offshore conditions over a normal December and is based upon 2453 predictions, one every 3 hours. The direction of the spokes show where quality surf generating swell comes from. Five colours represent increasing wave sizes. Very small swells of less than 0.5m (1.5 feet) high are shown in blue. Green and yellow represent increasing swell sizes and red represents the highest swells, greater than >3m (>10ft). In each graph, the area of any colour is proportional to how commonly that size swell occurs.
The diagram implies that the prevailing swell direction, shown by the biggest spokes, was ESE, whereas the the dominant wind blows from the ENE. 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 0.2% of the time, equivalent to 0 days. Open sea swells exceeding >3m (>10ft) are unlikely to happen in a normal December. Taking into account the proportion of these swells that coincided with forecast offshore winds, and given the fact that The Pass is slightly protected from open water swells, we think that that clean surf can be found at The Pass about 0.2% of the time and that surf is messed up by onshore wind 4% of the time. This is means that we expect 1 days with waves in a typical December, of which 0 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.