Backdoors Surf Stats

The rose diagram shows the variation of swells directed at Backdoors over a normal July and is based upon 3720 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast surf and wind right at the shore so we have chosen the most applicable grid node based on what we know about Backdoors, and at Backdoors the best grid node is 45 km away (28 miles). The rose diagram shows the distribution of swell directions and swell sizes, while the graph at the bottom shows the same thing but lacks direction information. Five colours illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. These were forecast only 1.9% of the time. Green and yellow show increasing swell sizes and red shows the biggest swells, greater than >3m (>10ft). In each graph, the area of any colour is proportional to how commonly that size swell happens. The diagram implies that the prevailing swell direction, shown by the biggest spokes, was SW, whereas the the prevailing wind blows from the WNW. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Backdoors 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 surfable at Backdoors, you can view an alternative image that shows only the swells that were expected to coincide with glassy or offshore wind conditions. During a typical July, swells large enough to cause good for surfing waves at Backdoors run for about 98% of the time.

read more