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Viana do Castelo ratings
Quality on a good day: 2.7
Consistency of Surf: 2.3
Difficulty Level: 1.3
Wind and Kite Surfing: 4.0
Crowds: 1.3

Overall: 3.3

See all 18 ratings

Based on 4 votes. Vote


Surf Report Feed

Viana do Castelo Swell Statistics, April: All Swell – Any Wind

The figure illustrates the combination of swells directed at Viana do Castelo through a typical April and is based upon 2880 NWW3 model predictions since 2007 (values every 3 hours). The wave model does not forecast wind and surf right at the coastline so we have chosen the most applicable grid node based on what we know about Viana do Castelo, and at Viana do Castelo the best grid node is 25 km away (16 miles).

The rose diagram describes the distribution of swell sizes and swell direction, while the graph at the bottom shows the same thing but without direction information. Five colours illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. These occurred only 5% of the time. Green and yellow represent increasing swell sizes and red shows the largest swells, greater than >3m (>10ft). In either 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 WNW, whereas the the most common wind blows from the NW. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Viana do Castelo and offshore. We combine these with the no surf category of the bar chart. To simplify things we don't show these in the rose plot. Because wind determines whether or not waves are clean enough to surf at Viana do Castelo, you can view an alternative image that shows only the swells that were expected to coincide with glassy or offshore wind conditions. Over an average April, swells large enough to cause surfable waves at Viana do Castelo run for about 95% 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.

FEATURE UPDATE: we now show red swell icons for 'open sea' swells that are travelling in an unfavourable direction for the surf break. In places, these swells may still wrap around coastlines and produce smaller waves at some breaks. They are also significant for windsurfers and other water users that tend to venture further off-shore.