The National Weather Service issued a warning Sunday to all those venturing near the Oregon coast this week: beware.

With waves expected to reach up to 20 feet over the course of the week, the Pacific Ocean seems to officially be transitioning from beach season into storm-watching season, ushering in a different brand of coastal travel.

Waves are expected to climb from 3 to 5 feet to 10 to 12 feet within a few days, the weather service warned, reaching a potential maximum height of 20 feet by Thursday. Those conditions could last through the weekend.

The warning might sound dire, but it is a regular occurrence on the Oregon coast.

“It’s not abnormal, it’s just the first time this year it’s happening,” said Rebecca Muessle, a meteorologist with the National Weather Service in Portland.

High seas this week are the result of a weather pattern moving in from the Gulf of Alaska, coming in from the north with a great deal of energy that pushes waves to greater heights. The last time the coast saw waves this size was in the spring, she said.

The swell will create dangerous conditions for those in boats, but also people making casual visits to the coast. Muessle said people should avoid beaches this week, as well as jetties and rocks jutting out into the ocean.

“This is not uncommon, but it doesn’t mean that it’s any less dangerous,” she said.

Storm watching is, however, a time-honored tradition on the Oregon coast, and there are plenty of safe places from which to watch the ocean as it crashes and churns. You can browse through our full list of good storm watching spots, but here are a few good ones on the northern Oregon coast, for those who want to make a day trip this week.

CAUTION: Make sure to watch from a safe distance and height. Stay off jetties and avoid low-lying areas like beaches and tide pools. Keep an eye out for sneaker waves on beaches. Do not venture beyond fences or other barriers, and stay away from cliff edges.

CAPE DISAPPOINTMENT

Found just across the Columbia River in Washington, Cape Disappointment is one of the best spots to watch waves cresting and crashing. It's also one of the most popular spots for storm watching, and gets crowded with photographers when a particularly big one rolls in. Head to Waikiki Beach for the best show.

FORT STEVENS

We named Fort Stevens the best state park in Oregon for many reasons, and storm watching happens to be one them. You can watch the ocean churn at the mouth of the Columbia River (nicknamed the "Graveyard of the Pacific"), or watch the weather come in over the Peter Iredale shipwreck, but one of the best spots to watch storms is from the platform overlooking the jetty on the Columbia.

ECOLA

With some of the most dramatic cliffside views of the Oregon coast, Ecola State Park is a natural place to watch storms roll in from the ocean, but what really makes it special is the Tillamook Rock Lighthouse, which is known to host spectacular scenes of crashing waves. Bring your binoculars or telephoto lens.

BOILER BAY

Boiler Bay is a great pull-off just north of Depoe Bay, used for a variety of purposes throughout the year, including bird watching and tide pooling. Come winter it's known as a dramatic place to see waves crash ashore, though once the wind and rain blow in you'll likely get soaked within seconds.

DEPOE BAY

Unlike beach towns built on sandy shores, Depoe Bay is perched atop the rocky cliffs of the north-central coastline, where waves spray through the town's famous spouting horn, and crash magnificently against (sometimes up and over) a towering sea wall in town. Be sure to dress in water-proof everything, or else be prepared to get wet.

--Jamie Hale | jhale@oregonian.com | @HaleJamesB