Bambra Reef Swell Statistics, Summer: All Swell – Any Wind
This picture illustrates the combination of swells directed at Bambra Reef over a normal southern hemisphere summer. It is based on 6365 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind or surf right at the coastline so we have chosen the best grid node based on what we know about Bambra Reef, and at Bambra Reef the best grid node is 67 km away (42 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 happened only 31% of the time. Green and yellow represent increasing swell sizes and red shows largest swells greater than >3m (>10ft). In each graph, the area of any colour is proportional to how often that size swell was forecast.
The diagram indicates that the most common swell direction, shown by the longest spokes, was SSW, whereas the the most common wind blows from the WNW. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Bambra Reef and away from the coast. We lump these in with the no surf category of the bar chart. To avoid confusion we don't show these in the rose diagram. Because wind determines whether or not waves are surfable at Bambra Reef, you can select a similar diagram that shows only the swells that were expected to coincide with glassy or offshore wind conditions. During a typical southern hemisphere summer, swells large enough to cause good for surfing waves at Bambra Reef run for about 27% 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.