Acid Drops Swell Statistics, Spring: All Swell – Any Wind
This image illustrates the variation of swells directed at Acid Drops through a typical northern hemisphere spring. It is based on 6580 NWW3 model predictions since 2007 (values every 3 hours). The wave model does not forecast wind and surf right at the shore so we have chosen the most applicable grid node based on what we know about Acid Drops. In the case of Acid Drops, the best grid node is 42 km away (26 miles).
The rose diagram describes the distribution of swell sizes and swell direction, while the graph at the bottom shows the same thing without direction information. Five colours represent increasing wave sizes. Very small swells of less than 0.5m (1.5 feet) high are shown in blue. These were forecast only 78% of the time. Green and yellow represent increasing swell sizes and red represents the largest swells, greater than >3m (>10ft). 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. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Acid Drops and away from the coast. We group these with the no surf category of the bar chart. To simplify things we don't show these in the rose diagram. Because wind determines whether or not waves are surfable at Acid Drops, you can select a similar diagram that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. Over an average northern hemisphere spring, swells large enough to cause good for surfing waves at Acid Drops run for about 22% of the time.
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.