Asu Swell Statistics, All Year: Surf with Light or Offshore Winds
The rose diagram shows only the swells directed at Asu that coincided with light winds or offshore conditions through a typical year and is based upon 28044 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 shows biggest swells greater than >3m (>10ft). In either graph, the area of any colour is proportional to how often that size swell happens.
The diagram indicates that the most common swell direction, shown by the biggest spokes, was SSW, whereas the the prevailing wind blows from the WSW. 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 67% of the time, equivalent to 245 days. Open sea swells exceeding >3m (>10ft) are unlikely to arise in a normal year but 12% of the time we expect swell in the range 2-3m (6.5-10ft) 12%, equivalent to (44 days). Taking into account the proportion of these swells that coincided with predicted offshore winds, and given the fact that Asu is exposed to open water swells, we think that that clean surf can be found at Asu about 67% of the time and that surf is blown out by onshore wind 33% of the time. This is means that we expect 365 days with waves in a typical year, of which 245 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.