Apache Pier Swell Statistics, Setembro: All Swell – Any Wind
The rose diagram illustrates the combination of swells directed at Apache Pier through a typical September. It is based on 2400 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 most applicable grid node based on what we know about Apache Pier. In this particular case the best grid node is 39 km away (24 miles).
The rose diagram illustrates the distribution of swell directions and swell sizes, while the graph at the bottom shows the same thing but lacks direction information. Five colours show increasing wave sizes. The smallest swells, less than 0.5m (1.5 feet), high are coloured blue. These occurred only 26% of the time. Green and yellow illustrate increasing swell sizes and largest swells greater than >3m (>10ft) are shown in red. In each graph, the area of any colour is proportional to how frequently that size swell happens.
The diagram suggests that the prevailing swell direction, shown by the longest spokes, was SE, whereas the the most common wind blows from the E. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Apache Pier and offshore. We lump these in with the no surf category of the bar chart. To simplify things we don't show these in the rose diagram. Because wind determines whether or not waves are clean enough to surf at Apache Pier, 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 September, swells large enough to cause surfable waves at Apache Pier run for about 74% 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.