Nungwi Reefs Surf Stats

The rose diagram describes the combination of swells directed at Nungwi Reefs through a typical May, based on 3440 NWW3 model predictions since 2007 (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 Nungwi Reefs. In the case of Nungwi Reefs, the best grid node is 38 km away (24 miles). The rose diagram describes the distribution of swell sizes and swell direction, while the graph at the bottom shows the same thing 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 only 6% of the time. Green and yellow represent increasing swell sizes and red shows highest swells greater than >3m (>10ft). In each graph, the area of any colour is proportional to how often that size swell happens. The diagram indicates that the most common swell direction, shown by the biggest spokes, was ESE, whereas the the dominant 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 Nungwi Reefs and out to sea. We combine these 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 Nungwi Reefs, you can select a similar diagram that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. Over an average May, swells large enough to cause good for surfing waves at Nungwi Reefs run for about 94% of the time.

read more