Nosy Andrea Surf Stats

This picture shows the range of swells directed at Nosy Andrea over a normal April. It is based on 2880 NWW3 model predictions since 2007 (values every 3 hours). The wave model does not forecast wind and surf right at the shore so we have chosen the most applicable grid node based on what we know about Nosy Andrea. In the case of Nosy Andrea, the best grid node is 25 km away (16 miles). The rose diagram describes the distribution of swell directions and swell sizes, 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 happened only 0.7% of the time. Green and yellow illustrate increasing swell sizes and red represents the biggest swells, greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how often that size swell was forecast. The diagram indicates that the prevailing swell direction, shown by the longest spokes, was SSW, whereas the the prevailing wind blows from the SSE. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Nosy Andrea and offshore. We group these with the no surf category of the bar chart. To keep it simple we don't show these in the rose diagram. Because wind determines whether or not waves are clean enough to surf at Nosy Andrea, you can view an alternative image that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. During a typical April, swells large enough to cause surfable waves at Nosy Andrea run for about 2.0% of the time.

read more