Emergency Management Term Definitions

Evacuation Stages

Evacuation Order: You are at risk. Leave the area immediately.

Evacuation Alert: Be ready to leave on short notice. If you leave before or during this alert, it’s called a voluntary evacuation.

Evacuation Rescind: All is currently safe and you can return home. Stay tuned for other possible Evacuation Alerts or Orders.

Tsunami Alert Levels

Warning: This is the highest level of tsunami alert. Warnings are issued due to the imminent threat of a tsunami from a large undersea earthquake, or following confirmation that a potentially destructive tsunami is underway. They may initially be based only on seismic information as a means of providing the earliest possible alert. Warnings advise that appropriate actions be taken in response to the tsunami threat. Such actions could include the evacuation of low-lying coastal areas.

Advisory: This is the second highest level of tsunami alert. Advisories are issued due to the threat of a tsunami that has the potential to produce strong currents dangerous to those in or near the water. Significant inundation is not expected for areas under an Advisory but coastal zones may be at risk due to strong currents. Appropriate actions by local emergency management personnel may include closing beaches and evacuating harbours and marinas.

Watch: This is the third highest level of tsunami alert. Watches are based on seismic information, without confirmation that a destructive tsunami is underway. There is a potential threat to a zone under a tsunami Watch but communities have time to prepare. Emergency management personnel and coastal residents should prepare to take action in case the Watch is upgraded.

Cancellation: A “cancellation” cancels any previously issued tsunami messages. It is issued when there is no longer observed evidence of tsunami waves at tide gauge stations. Local conditions may differ from those at tide gauge stations and local authorities should determine the safety of coastlines. Once a cancellation has been issued for a tsunami event, EMBC will no longer issue tsunami messages.

Flooding Terms

Flood Warning: River levels have exceeded bankfull or will exceed bankfull imminently, and that flooding of areas adjacent to affected rivers will result.

Flood Watch: River levels are rising and will approach or may exceed bankfull. Flooding of areas adjacent to affected rivers may occur.

High Streamflow Advisory: River levels are rising or expected to rise rapidly, but no major flooding is expected. Minor flooding in low-lying areas is possible.