What’s the difference between a tsunami advisory and a tsunami warning?

SAN FRANCISCO (KRON) — The San Francisco Bay Area was under a tsunami advisory overnight Tuesday into Wednesday morning after a massive earthquake off the East Coast of Russia Tuesday. The quake first triggered a tsunami watch for the entire West Coast of the United States.

That watch was later changed to an advisory, leading to some confusion about whether an advisory was an upgrade or a downgrade from a watch. According to the National Weather Service, an advisory is a higher level of alert than a watch.

What is a tsunami watch?

Under a tsunami watch, a tsunami is possible, according to the NWS, but the arrival time is still several hours away. People are advised to prepare now, but the alert level is still subject to change.

The weather service advises people to:

• Prepare to take action
• Monitor local TV, radio, social media
• Listen to NOAA weather radio

What is a tsunami advisory?

Under a tsunami advisory, the NWS warns of strong currents and dangerous waves in or near coastal waters. When an advisory is in effect, people are advised to “Stay out of the water and away from the shore.”

What is a tsunami warning?

A tsunami warning is the highest level of alert. It implies that a tsunami is imminent along with flooding and dangerous currents.

When a tsunami warning is in effect, the NWS advises people to “Get to high ground or inland immediately,” and to “follow evacuation signage.”

What is an information statement?

This is the lowest level of tsunami alert. It means that no tsunami is expected and no action is required.

As of Wednesday morning, the tsunami advisory has been canceled for San Francisco and much of the California coast. Stick with KRON4.com for the latest coverage on the Bay Area tsunami alert.