North America

North America’s west coast faces the expansive Pacific; the east braves the stormy North Atlantic and Gulf of Mexico. Even though all northern latitudes lie in the low pressure westerly wind zone and subtropical areas are mostly influenced by high pressure, wind and weather patterns differ greatly between the two coasts. When it comes to swell supply it also matters whether you rely on the front or tail end of weather systems, giving the west coast a definite advantage.

Another stark fact at subtropical latitudes is that water temperatures are significantly lower on the west coast compared to the same latitude out east. On the west coast, the North Pacific’s north-south flowing California Current feeds cool water south, an effect tangibly reinforced by rising deep water ‘upwellings’. Meanwhile, the east coast is warmed by the north-flowing Gulf Stream – a phenomenon that still tempers Europe’s higher latitudes, way across Atlantic.

Summer is favourite on the west coast – and not just because of the temperature. A north-westerly airflow develops parallel to shore on the edge of stable high pressure over the Pacific. Plus there’s a huge temperature difference between the cool Pacific and sun-drenched land, creating a rideable sea breeze all the way up to Vancouver Island in Canada. This thermal is especially noticeable further south, where backcountry Oregon, California, Nevada, Arizona and New Mexico get really toasty. When a local venturi effect like in the Central Gorge adds to this, windspeeds can easily reach 30 knots and beyond. “Life begins at 40 knots”, rave the high wind aficionados! Reliable NW winds of around 15-25 knots blow in the San Francisco Bay Area as well as Central & Southern California all the way south to Ventura. LA lies in the wind shadow of an eastward-bound coastline, but the thermal works nicely again for several hundred kilometres below San Diego into Baja California (see ‘Central America & Caribbean’ bundle). In wintertime the high pressure systems are weaker and track further south. The NW winds become correspondingly unreliable (except for the very south of California) and increasingly frequent low pressure systems dominate the cooler, much more humid weather.

The Pacific coast isn’t just spectacularly picturesque, it also offers amazing waves. The best swell generators are the North Pacific’s huge low pressure systems which form year-round between 30º and 60º North and move eastward. In winter they first supply Hawaii with the largest waves on the planet before hitting the west coast, sized XL – the further north you are, the bigger. Sadly, during the best wind in summertime the waves are only half as big as the low pressure systems track further north. Sometimes you can catch a long-distance south swell from the southern hemisphere or some short-lived stuff from hurricanes (‘chubascos’), which can rage off the Mexican west coast from July until September. For wave seekers, the transitional months are most interesting – particularly spring, which can score the best of both worlds.

On the east coast, stable Bermuda High systems dominate the summer. On their backside it blows mostly from the south. Winter sees northerly wind created by high pressure systems tracking across the mainland. Starting in North Carolina these are increasingly interspersed with westerlies and more low pressure influence.

On South Padre Island, south-easterly wind created by high pressure over the Gulf of Mexico is accelerated onshore by a heat induced low over the mainland – spring and autumn are especially windy. Gulf summers are so hot that the thermal effect is weaker. With water temperatures breaking 26°C, hurricane season (Jul-Nov) starts. When a storm isn’t directly ravaging the region, it can yield a few (very rainy) high wind days – and best of all, good swell. Apart from irregular hurricane activity, Southern Florida doesn’t usually get much wind in the summer. But with its warm Gulf Stream water, it’s pleasant winter riding when cold fronts supply the region with northerlies. On the Outer Banks, Cape Hatteras’ season starts in March and runs into November. The high pressure dominated summer there breeds reliable SW winds, the transitional months have NE winds from the mainland or low pressure westerlies. The further north you go, the more variable both weather and conditions become. Even though Cape Cod’s summers are still dominated by high pressure southerlies, year-round low pressure activity increases markedly above 40º North. In Canadian New Brunswick, the Acadian Islands sit fully in the westerly wind zone but temperatures only allow a 5-month summer season.

Hurricanes are the east coast’s best swell producers; developing in the Atlantic north of the equator from July to November. They usually take aim at the Caribbean or Gulf of Mexico before swinging back NE and out to the Atlantic. Good as the resulting swell might be, predicting the exact path of each storm is impossible – which makes these months seriously dicey for the Southern States. By the time they reach North Carolina, the systems have usually weakened enough to render them relatively safe. During winter (October to March) the main swell producers are Atlantic low pressure systems moving east, away from Nova Scotia. Since only NE swell on the backsides of these cyclones reaches America, the waves here never gets as big and are tamer than on the far side of the Atlantic in Europe. However, swell sizes of 3-4m up north and 2-3m in Florida are possible.

The tidal range of most North American regions is below 2m. British Columbia on the west coast can see up to 3.5m, but the further south you go, the smaller it gets.