Porth Colmon Surf Stats

The graph describes the variation of swells directed at Porth Colmon through a typical August and is based upon 3589 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast surf and wind right at the coastline so we have chosen the best grid node based on what we know about Porth Colmon. In this particular case the best grid node is 18 km away (11 miles). The rose diagram describes the distribution of swell directions and swell sizes, 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 49% of the time. Green and yellow represent increasing swell sizes and red shows the highest swells, greater than >3m (>10ft). In both graphs, 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 longest spokes, was SW, whereas the the dominant wind blows from the WSW. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Porth Colmon and offshore. We group these with the no surf category of the bar chart. To avoid confusion we don't show these in the rose plot. Because wind determines whether or not waves are good for surfing at Porth Colmon, you can view an alternative image that shows only the swells that were expected to coincide with glassy or offshore wind conditions. Over an average August, swells large enough to cause clean enough to surf waves at Porth Colmon run for about 2.0% of the time.

read more