South America

Just like North America, conditions on the South American continent vary greatly between east and west. It’s equally obvious that the west coast is oriented towards the front-side and the east coast the tail-end of weather systems. Most of all though, opposing ocean currents make for dramatic climatic differences that in turn immensely influence the winds.

While the Brazil Current on the east coast feeds warm water southward, the Humboldt Current carries cold water from Antarctic waters way north along the west coast. Below 40° South the water’s bound to be bitterly cold, but even up near Santiago the temperature hovers around just 13-17°C (16-21°C in northern Peru). The world’s coolest equatorial waters are still recorded on the Galapagos Islands. The cold water creates a cool layer of air, above which lie dry, warm air-masses in a narrow coastal strip between the Pacific and Andes looming 6,000m above. These are ideal conditions for an extremely dry climate, as also seen on the coast of Namibia and (to a lesser extent) California and Western Australia. From Santiago north this effect gets more marked until Atacama, the driest desert on Earth, at Chile’s border with Peru. In a climate like this, especially in the cooler seasons, dense sea-fog (rather than raincloud) often develops that can sometimes hang around for days on end.

But every 6-8 years it’s a completely different story as the warm water El Niño current appears off northern Peru around Christmas. It doesn’t surrender to the Humboldt Current for a year or two, expanding further south instead. Devastating rainfall unloads along the west coast, and without the land / ocean temperature gradient the wind stays away. El Niño years are therefore a no-go.

Otherwise the wind mechanism along South America’s west coast sounds relatively simple. The cold coasts of Patagonia below 40° South are located in the stormy westerly wind zone year-round, north of which stable high pressure areas hang over the South Pacific. Southerly winds dominate along their rim, accelerated along the coast by the Andes and thermally strengthened by the temperature difference between cold Pacific and warm landmass. In the summer (Oct-Mar) when high pressures centre further south and the thermal works best, the southerly wind is also reliable in Southern Chile, although low pressure dominates the winter weather. With a steeper temperature gradient, Northern Chile enjoys year-round wind, albeit a little lighter. Conditions along Peru’s Costa Sur are even better, with wind all year plus a bit more sun ensuring the thermals are more reliable in summertime. Peru’s Costa Norte has more wind from autumn to spring though, which coincides with prime wave season.

The storms between New Zealand and Cape Horn are particularly strong in the austral winter, so the waves are at their biggest with frequent high-quality swell of 13 to 18 second periods. Southward, swell heights increase towards 40° South so even comparably small summer swell is often still good for mast-high days in Southern Chile. Peru and Chile get their illustrious nickname ‘Land of the Lefts’ from coasts that are perfectly aligned for the dominant SW swell, fully furnished with quality point-breaks. Northern Peru also catches winter swell after a long journey across the North Pacific from Aleutian low pressure.

Swell supply is the striking difference on South America’s east coast. Conditions rely on the tail-ends of storms moving east from Cape Horn, so there’s less and generally shorter-lived groundswell than on the west coast. Furthermore the South Atlantic is the world’s only ocean without tropical cyclones, ruling out another potential swell producer. Any groundswell reaching Brazil’s north coasts has travelled a long way through the North Atlantic, so it’s usually pretty average. Hence the east coast generally relies on localised windswell, although Atlàntida Argentina and Santa Catarina in stormier latitudes do make the best of it. What’s more, Santa Catarina’s exposed location means it still scores decent groundswell of 3m and more in its wind-rich winter and spring.

Year-round high pressure over the South Atlantic supplies the east coast with wind. North-easterlies dominate the western rim, but are often interrupted by lows in Atlántida Argentina and Santa Catarina, especially in winter. On the system’s northern rim, reliable SE trades develop along Brazil’s north coasts. Windspeed and reliability increase from Rio Grande do Norte across Eastern Ceara all the way to Northwest Ceara thanks to thermal reinforcement from the hinterland. The wind’s a bit unreliable in rainy season (Mar-May), but otherwise Ceara’s wind stats are legendary. And what the region lacks in waves, it compensates for with tropical temperatures and Brazilian lust for life. The mountain lakes of Argentina are utterly remote. Summer thermals turn southern Atlàntida Argentina further north into the most reliable (high wind) areas of the whole country.

Year-round neoprene’s a must on the west coast, at best you might regularly get away with a shorty up in the far north of Peru. It’s the same story on the east coast all the way to Santa Catarina, beyond which the Brazilian regions near the equator are pure boardshorts destinations. The tidal ranges on the west coast are all below 2m, but can significantly influence sensitive point-breaks. Large tidal ranges occur on the east coast in southern Patagonia and all around the Amazon delta. In Ceara they still reach 3m, which doesn’t influence the beach-breaks much, but vastly effects the size and depth of most lagoons.