If you want to see how quickly surf can change, stake out the North Shore today.

Surf has been 2 feet or less along the North Shore overnight and early this morning, but it will build to 6 to 8 feet and by later this afternoon is expected to reach 14 to 18 feet, the National Weather Service said.

Surf is also on the rise along west shores, where it will climb from 4 to 6 feet this morning to 8 to 11 feet by late this afternoon.

High surf advisories will be in effect for both shores.

Surf along east shores will be 3 to 5 feet today, while in town the surf along south shores will be a very mild 1 to 3 feet.

Lifeguards on the North Shore reported this morning being mostly flat, but buoys are reading new energy so Ocean Safety officials are expecting a rapid rise in surf, Emergency Services spokesman Bryan Cheplic said.

"It should be a rapid rise and the surf should peak sometime tomorrow," Cheplic said. "Anyone coming out should use caution before going into the water and check with lifeguards to make sure it's safe."

For more on beach conditions, go to hawaiibeachsafety.org.

The high surf advisory for north-facing shores will continue through Tuesday.