The Pacific Ocean near Depoe Bay, Oregon on April 22, 2018. Photo: Chas Hundley

A Tsunami Advisory has been issued for most of the West Coast, including Oregon, following a massive underwater volcano Friday afternoon in the Pacific Ocean near the Tonga Islands.

Issued just before 5 a.m. Saturday, the National Weather Service said that waves of between one and three feet could strike the coast. Locally, the tsunami could strike the Seaside area around 8:45 a.m.

"Tsunami advisories mean that a tsunami capable of producing strong currents or waves dangerous to persons in or very near the water is expected or is already occurring," The NWS said

Adding to the advisory, the Portland office of the NWS issued a special weather statement for the Oregon coast, noting that a tsunami had been confirmed.

"A tsunami capable of producing strong currents that may be hazardous to swimmers, boats, and coastal structures is expected. Widespread inundation is NOT expected," the NWS said.

The NWS and other officials urged people to evacuate the beach, harbors, and marinas, and to follow instructions from local emergency officials.

"Do not go to the coast to watch the tsunami," the NWS said.

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The advisory stretches from the California-Mexico border and extends to Attu, Alaska.

"Tsunamis often arrive as a series of waves or surges which could be dangerous for many hours after the first wave arrival, the NWS said in a statement. "The first tsunami wave or surge may not be the highest in the series."

The NWS said it could strike the Southern Oregon coast starting around 7:55 a.m.

One to two and-a-half foot waves were observed in Hawaii as a result of the volcano.

This is a developing story and will be updated.