Grotta Surf Stats

The figure illustrates the variation of swells directed at Grotta over a normal May, based on 3398 NWW3 model predictions since 2007 (values every 3 hours). The wave model does not forecast wind or surf right at the coast so we have chosen the best grid node based on what we know about Grotta, and at Grotta the best grid node is 30 km away (19 miles). The rose diagram illustrates the distribution of swell sizes and swell direction, while the graph at the bottom shows the same thing but lacks 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 occurred only 48% of the time. Green and yellow represent increasing swell sizes and red illustrates the largest swells, greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how commonly that size swell occurs. The diagram implies that the prevailing swell direction, shown by the largest spokes, was WSW, whereas the the most common wind blows from the ENE. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from Grotta and out to sea. We lump these in with the no surf category of the bar chart. To avoid confusion we don't show these in the rose graph. Because wind determines whether or not waves are clean enough to surf at Grotta, you can select a similar diagram that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. During a typical May, swells large enough to cause surfable waves at Grotta run for about 52% of the time.

read more