Quintana Jetty Swell Statistics, July: All Swell – Any Wind
This picture shows the combination of swells directed at Quintana Jetty through a typical July and is based upon 2480 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind and surf right at the coast so we have chosen the most applicable grid node based on what we know about Quintana Jetty. In this particular case the best grid node is 19 km away (12 miles).
The rose diagram illustrates 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 were forecast 54% of the time. Green and yellow illustrate increasing swell sizes and biggest swells greater than >3m (>10ft) are shown in red. In both graphs, the area of any colour is proportional to how often that size swell occurs.
The diagram indicates that the dominant swell direction, shown by the biggest spokes, was SE, whereas the the prevailing wind blows from the S. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Quintana Jetty and away from the coast. We group 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 good for surfing at Quintana Jetty, you can view an alternative image that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. Over an average July, swells large enough to cause clean enough to surf waves at Quintana Jetty run for about 46% 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.