Acid Drops Swell Statistics, Spring: Surf with Light or Offshore Winds
The rose diagram shows only the swells directed at Acid Drops that coincided with light winds or offshore conditions through a typical northern hemisphere spring and is based upon 6580 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 illustrate increasing swell sizes and largest swells greater than >3m (>10ft) are shown in red. In either graph, the area of any colour is proportional to how commonly that size swell happens.
The diagram implies that the most common swell direction, shown by the biggest spokes, was S, whereas the the most common 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 19% of the time, equivalent to 17 days. Open sea swells exceeding >3m (>10ft) are unlikely to arise in a normal northern hemisphere spring but 12% of the time you can expect swell in the range 1.3-2m (4-6.5ft) 12%, equivalent to (11 days). Taking into account the fraction of these swells that coincided with expected offshore winds, and given the fact that Acid Drops is exposed to open water swells, we calculate that clean surf can be found at Acid Drops about 19% of the time and that surf is blown out by onshore wind 3% of the time. This is means that we expect 20 days with waves in a typical northern hemisphere spring, of which 17 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.