California surf forecast

California gets surf from two directions and two hemispheres, which is what makes its season so long. Winter brings North Pacific groundswell generated by storms off the Aleutians and the Gulf of Alaska — long-period, powerful, and the reason Mavericks exists. Summer brings Southern Hemisphere swell that has travelled from storms below New Zealand, arriving smaller but with enormous period after a journey of 5,000 miles or more.

The coastline itself does the sorting. Point Conception splits the state into a north-facing stretch exposed to everything the North Pacific throws at it, and a south-facing bight below it that is shadowed from northwest swell and comes alive on south. That single geographic fact explains most of why two breaks 100 miles apart can be firing and flat on the same day.