Storm surge

A storm surge reflects the difference between the actual water level under the influence of a meteorological disturbance (storm tide) and the level which would have occurred in the absence of the meteorological disturbance (WMO, 2008, 2011, 2017).

A storm surge is the rise in seawater level caused solely by a storm. It is the abnormal rise in seawater level during a strom, measures as the height of the water above the normal predicted astronomical tide. The surge is caused primarily by a storm's winds pushing water onshore.

Storm surge should not be confused with storm tide. A storm tide is the water level that results from the combination of the storm surge and the normal (astronomical tide).

This rise in water level can cause extreme flooding in coastal areas, resulting from storm tides reaching up to 6 meters (20 feet) or more in some cases (NOAA, 2019b.) On top of a strom tide are pounding waves generated by the powerful winds. The area of seawater flooding may extend along the coast for over 100 km, with water pushing several kilometres inland if the land is low lying. The combined effects of the storm tide and surface waves can destroy buildings, wash away roads and run ships aground (Australian Government, 2020).

Examples of National Alerting Parameters include storm surge warning issued in Canada (Government of Canada, 2019) and an Advisory for storm surge watch/warning issued by the World Meteorological Organization (WMO, 2017).

Different symbols of hazards and disasters.

See all hazards

Latest Storm surge additions in the Knowledge Base

UN resolutions and reports

22 August 2023

Combating sand and dust storms - Report of the Secretary-General (A/78/237)

A/78/237

The present report, submitted pursuant to General Assembly resolution 77/171 on combating sand and dust storms, provides details on developments within the United Nations system and covers the period from mid-2022 to mid-2023.

Update

3 August 2023

NASA SPoRT’s lightning prediction tool provides critical weather forecasting support at Rock the South

On Friday, July 21st, 2023, over 35,000 people were denied entry to Rock the South’s outdoor country music festival in Cullman, Alabama at 3 P.M. due to the threat of lightning in the area.

National Aeronautics and Space Administration

Update

5 August 2023

Storm Antoni: why naming storms is a risky business

Since 2015, the UK’s Met Office has used forenames to label storms, as a strategy for improving people’s awareness of severe weather warnings.

Conversation Media Group, the

View from dune top over sunset in North Sea from the island of Ameland, Friesland, Netherlands

Update

28 July 2023

Plants build dunes but can speed erosion during severe storms

When waves hit vegetated dunes, waterlogged areas form in front of plants, making for sand that’s easier to wash away. But you still need plants to form dunes in the first place.

Eos - AGU

Research briefs

24 July 2023

Long-term changes in waves and storm surges have not impacted global coastlines

Changes in ocean wave and storm conditions have not caused long-term impacts on sandy coastlines in the past 30 years, a new study has found.

University of Melbourne

Street corner in Beijing during a Sandstorm.

Update

18 July 2023

China and Mongolia team up to fight sandstorms

Mining and climate change are damaging the grasslands that prevent sandstorms. Can greater cooperation help?

China Dialogue

Update

12 July 2023

WMO highlights efforts to tackle sand and dust storms

The World Meteorological Organization is supporting the first ever International Day of Combating Sand and Dust Storms to draw attention to the significant impacts on the environment, socio-economic well-being and health.

World Meteorological Organization (WMO)

Aerial view of coastline of the Seychelles.

Update

12 July 2023

Climate threat: Rising sea levels and stronger storms highlight the need for coastal resilience

Climate change is threatening coastal communities worldwide. Using local knowledge, as well as innovative practices such as parametric insurance, is needed to enhance coastal resilience and mitigate the impact of climate change.

Asian Development Bank (ADB)