Gerroa (7 Mile Beach) Surf Stats

The rose diagram describes the range of swells directed at Gerroa (7 Mile Beach) over a normal May, based on 3192 NWW3 model predictions since 2007 (values every 3 hours). The wave model does not forecast wind and surf right at the coastline so we have chosen the optimum grid node based on what we know about Gerroa (7 Mile Beach). In this particular case the best grid node is 31 km away (19 miles). The rose diagram shows the distribution of swell sizes and directions, while the graph at the bottom shows the same thing but 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 20% of the time. Green and yellow illustrate increasing swell sizes and red illustrates highest swells greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how frequently that size swell was forecast. The diagram suggests that the most common swell direction, shown by the largest spokes, was SE, whereas the the dominant wind blows from the W. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Gerroa (7 Mile Beach) and offshore. We combine these 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 good for surfing at Gerroa (7 Mile Beach), you can select a similar diagram that shows only the swells that were expected to coincide with glassy or offshore wind conditions. During a typical May, swells large enough to cause clean enough to surf waves at Gerroa (7 Mile Beach) run for about 52% of the time.

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