Johanna Surf Stats

The figure describes the combination of swells directed at Johanna through an average June, based on 3506 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind or surf right at the coastline so we have chosen the most applicable grid node based on what we know about Johanna. In this particular case the best grid node is 25 km away (16 miles). The rose diagram describes the distribution of swell sizes and directions, 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 happened only 15% of the time. Green and yellow represent increasing swell sizes and red shows highest 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 largest spokes, was SW, whereas the the dominant wind blows from the WNW. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Johanna and away from the coast. We combine these with the no surf category of the bar chart. To simplify things we don't show these in the rose graph. Because wind determines whether or not waves are surfable at Johanna, you can select a similar diagram that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. In a typical June, swells large enough to cause good for surfing waves at Johanna run for about 85% of the time.

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