With coastal water temperatures dropping as we head into the winter season, you may think it’s time for all those surfers to find a new hobby, but peak surf season is just getting started. Some of you may know that winter has the potential to bring good surf to San Diego, but what’s the science behind it?

Ultimately, it’s the strong winds from winter storms that fuel the season’s best surf. According to the National Oceanic and Atmospheric Administration, the powerhouse generating many of these storms is the polar front, a boundary where cold, dry air from the Arctic meets the warm, wet air from the mid-latitudes. The resulting winds, in addition to the force from Earth’s rotation, create a whipping belt of winds known as the polar jet stream. As temperatures drop across the United States during the winter months, the polar jet extends down from the Arctic and into the North Pacific, driving many of the North Pacific’s winter storms.

These storms create what is known as a “swell” or waves that travel outward from the storms until they reach coastlines in the form of organized, consistently breaking waves. According to the administration, the continental United States is expected to see La Niña-type conditions, leaving warmer and drier conditions due to the polar jet lingering north. By contrast, El Niño conditions mean an amplified Pacific Jet, which brings lots of precipitation-producing storms to the Southern United States. The Inertia,a surfing magazine, said when these storms bend south, California receives “much-needed” precipitation, but when they stay north, the weather stays clear while still delivering swells to the California coast.

The administration said La Niña does not mean there won’t be any storm activity this winter. During last year’s La Niña event in December, the resulting swell brought long-period waves in excess of 15 feet at Black’s Beach.

According to San Diego Surf School, Black’s is one of the spots that flourish when swells from the North Pacific hit California. Due to their geography and the facing direction of the beaches, the surf school says La Jolla Shores and Sunset Cliffs are also prime spots during northern swells in the winter.