All Day Bay Swell Statistics, April: Surf with Light or Offshore Winds
The rose diagram shows only the swells directed at All Day Bay that coincided with light winds or offshore conditions over a normal April. It is based on 2160 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 illustrate increasing swell sizes and red illustrates the biggest swells, greater than >3m (>10ft). In either graph, the area of any colour is proportional to how commonly that size swell occurs.
The diagram implies that the dominant swell direction, shown by the longest spokes, was SSE, whereas the the prevailing wind blows from the NW. 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 38% of the time, equivalent to 11 days. Open water swells exceeding >3m (>10ft) only happen 1.7% of the time in a typical April, equivalent to just one day but 9% of the time we expect swell in the range 2-3m (6.5-10ft) 9%, equivalent to (3 days). Taking into account the ratio of these swells that coincided with predicted offshore winds, and given the fact that All Day Bay is exposed to open water swells, we think that that clean surf can be found at All Day Bay about 38% of the time and that surf is messed up by onshore wind 29% of the time. This is means that we expect 20 days with waves in a typical April, of which 11 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.