But surfers are smiling.

The National Weather Service today stuck by its forecast of 35- to 50-foot wave faces by sunrise tomorrow. The weather service issued a high-surf warning for north- and west-facing shores through tomorrow night.

The combination of waves and an extreme high tide — 2.5 feet at 6:56 a.m. — will likely push surf over coastal roads and damage property, the weather service predicted.

Waves that large, however, are more than enough for organizers to send surfers into Waimea Bay for the 20th Anniversary Quiksilver In Memory of Eddie Aikau Big Wave Invitational, said contest spokeswoman Jodi Young. The first heats should begin at 8 a.m., she said.

Only elite surfers are invited and in 19 years, the surf has only been large enough for the contest to be held six times. Waves have to be at least 20 feet under the traditional, Hawaiian-style measurement, which is roughly half to two-thirds as large as the wave-face scale used by the weather service. The contest organizers are expecting Hawaiian scale waves of 25-feet, Young said.

"We are good to go," Young said today. "Everybody is pretty excited."

Well, everybody except the city's North Shore lifeguards, who expect some of the largest crowds of the young winter surf season.

"We're just concerned that there will be a lot of people out on the North Shore and it impacts our ability to provide emergency services," said city lifeguard Lt. John Hoogsteden.

Drivers stuck in traffic tend to get frustrated, park on the side of the road and walk too close to the water's edge, he said.

"They are standing where they think it is calm and then a big wave comes along and smashes them," he said.

Often, they are dragged over rocks and badly cut, he said.

"Be smart and stay a safe distance away from the ocean," he said. "And don't expect to go surfing."

All of the O'ahu Civil Defense volunteers along the North Shore have been put on alert. They haven't had to deal with surf this large since January 2003.

"We are working closely with the police and ocean safety," Peter Hirai, plans and operations manager for the agency. "We have been notifying as many people as we can on the North Shore, just warning them to be prepared."

Overnight spot checks will be made of areas where waves have washed over the highway during previous high-surf episodes, he said.

"Especially with it this high, they will be diligent in checking it," Hirai said.

The civil defense agency is urging residents and beachgoers to avoid the surf and stay out of the water. Residents should also be ready to evacuate their homes, the agency warned. It also wants motorists in the area to drive with caution because highways can become clogged with sand or debris.