Why is the surf chart graph sometimes bigger, but the swell is smaller?
For instance: http://www.swellinfo.com/surf-foreca...lifornia-north
On this chart on Sunday at 9am it's going to be 2.1 feet (waist level), but the graph looks bigger on Wednesday at 9am, (chest level) but it's only 1.6 feet.
There could be several reasons, but in this case, its due to the long 19 second period.
Other reasons, why this may happen, is the combination of multiple swell groups, creating higher overall surf heights then if taking individual swell components alone. This is one of the least understood scenarios in surf forecasting.