Tsunami alerts: warning, advisory, watch, and natural signs

Read the exact alert level

Warning, advisory, watch, and information statement are different products

NOAA's tsunami warning centers issue messages for U.S. and Canadian coastlines after a possible tsunami-generating event. The message can change as earthquake analysis, sea-level observations, and forecast information improve, so keep checking official updates until local officials say the danger has ended.

Tsunami Warning

Take action. A tsunami capable of widespread flooding is expected or occurring. Follow evacuation instructions and move inland or to high ground away from the water.

Tsunami Advisory

Take action near the shore. Strong currents or waves dangerous to people in or very near the water are expected or occurring. Stay out of the water and away from beaches and waterways.

Tsunami Watch

Be prepared. A distant earthquake has occurred and a tsunami is possible, but the danger is not yet known. Monitor updates and be ready to move if the watch is upgraded.

Information Statement

An earthquake occurred, but there is no threat, it was far away, or the threat has not been determined. Read the full message; most statements indicate no destructive threat.

Do not mix product types

Outlooks and forecasts are not the same as a tsunami watch or warning

The familiar weather words describe different levels of information. For tsunami safety, the official product name and the action in the message matter more than a color or a headline from another source.

Natural warning signs

Near the coast, the earthquake or ocean may warn you first

A local tsunami may arrive before an official message reaches every person. NWS guidance identifies three natural warnings: strong or long earthquake shaking, a sudden rise or fall of the ocean, or a loud roar from the ocean. One sign is enough to act.

1. During shaking, drop, cover, and hold on. Expect aftershocks.
2. As soon as you can move safely, leave the beach, harbor, marina, and low-lying coastal area.
3. Follow marked evacuation routes toward high ground or inland. If no route is visible, go as high or as far from the water as you safely can.
4. Do not wait for an official warning, siren, phone alert, or confirmation from social media.
5. Once safe, use NOAA Weather Radio, local officials, Tsunami.gov, radio, television, or mobile data for updates.

An unusual retreat of the water is not an invitation to approach the exposed shore. It can be a natural tsunami warning. Move away immediately and tell others as you go without delaying your own evacuation.

Plan the route before you need it

Know whether your home, hotel, school, or workplace is in a hazard zone

Tsunami risk is local. Coastal communities may publish hazard maps, evacuation zones, vertical-evacuation locations, and route signs. Visitors should learn the route when they arrive, not after an earthquake. A road that leads along the shore is not a substitute for a marked route away from the water.

• Identify a safe destination outside the local hazard or evacuation zone.
• Practice reaching it on foot; roads may be damaged or congested after an earthquake.
• Keep sturdy shoes, essential medication, water, and a compact emergency kit accessible.
• Include children, older adults, people with disabilities, pets, and visitors in the plan.
• Keep Wireless Emergency Alerts enabled and use more than one warning method.

The danger can last

The first wave may not be the largest—and an initial drop does not mean all-clear

A tsunami is a series of waves and powerful currents. Dangerous conditions may continue for hours or days after the first arrival. Harbors, river mouths, bays, beaches, and other waterways can remain hazardous even when the water briefly appears calmer.

• Stay outside the evacuation or hazard zone until local officials say it is safe.
• Do not return to watch, photograph, or inspect the shoreline.
• Avoid floodwater, damaged roads, downed power lines, unstable buildings, bridges, and piers.
• Use calls only for emergencies when officials ask the public to keep communications open.
• Continue monitoring official updates because a watch or advisory can be upgraded, changed, or cancelled.