Punta Roquitas Swell Statistics, January: All Swell – Any Wind
This picture shows the combination of swells directed at Punta Roquitas over a normal January, based on 1728 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 best grid node based on what we know about Punta Roquitas. In this particular case the best grid node is 43 km away (27 miles).
The rose diagram shows 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 happened only 0% of the time. Green and yellow represent increasing swell sizes and red illustrates the biggest swells, greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how commonly that size swell was forecast.
The diagram implies that the prevailing swell direction, shown by the longest spokes, was SW, whereas the the prevailing wind blows from the S. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from Punta Roquitas and out to sea. We combine these with the no surf category of the bar chart. To simplify things we don't show these in the rose plot. Because wind determines whether or not waves are surfable at Punta Roquitas, you can load a different image that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. During a typical January, swells large enough to cause good for surfing waves at Punta Roquitas run for about 82% 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.