Ala Moana Bowls Swell Statistics, December: Surf with Light or Offshore Winds
This image shows only the swells directed at Ala Moana Bowls that coincided with light winds or offshore conditions over a normal December and is based upon 2457 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 show increasing swell sizes and red represents 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 most common swell direction, shown by the biggest spokes, was S, whereas the the prevailing wind blows from the E. 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 4% of the time, equivalent to 1 days. Open sea swells exceeding >3m (>10ft) are unlikely to arise in a normal December. Taking into account the proportion of these swells that coincided with predicted offshore winds, and given the fact that Ala Moana Bowls is exposed to open water swells, we calculate that clean surf can be found at Ala Moana Bowls about 4% of the time and that surf is spoilt by onshore wind 8% of the time. This is means that we expect 4 days with waves in a typical December, of which 1 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.