Cliff Beach (Lewis) Swell Statistics, February: All Swell – Any Wind
The rose diagram describes the range of swells directed at Cliff Beach (Lewis) through an average February, based on 2032 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 best grid node based on what we know about Cliff Beach (Lewis), and at Cliff Beach (Lewis) the best grid node is 25 km away (16 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 illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. These happened only 14% of the time. Green and yellow show increasing swell sizes and red illustrates the highest swells, greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how frequently that size swell occurs.
The diagram suggests that the prevailing swell direction, shown by the longest spokes, was WNW, whereas the the dominant wind blows from the SW. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from Cliff Beach (Lewis) and out to sea. We lump these in 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 good for surfing at Cliff Beach (Lewis), you can view an alternative image that shows only the swells that were expected to coincide with glassy or offshore wind conditions. In a typical February, swells large enough to cause clean enough to surf waves at Cliff Beach (Lewis) run for about 86% 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.