What term means the abnormal rise of seawater generated by a storm?

The abnormal rise of seawater generated by a storm is called a storm surge.

Storm surge occurs when strong winds push ocean water toward the coast, especially across a long stretch of open water. A storm’s low atmospheric pressure also allows the sea surface to rise slightly. The greatest surges usually occur where shallow coastal waters, coastline shape, and storm direction concentrate the water.

A storm surge is measured above the normal astronomical tide and does not include wind-driven waves. When surge arrives on top of a high tide, the combined water level is often called a storm tide. That distinction matters because waves riding on the surge can cause additional destruction, even though they are not technically part of the surge itself.

The term is often confused with a tsunami, but the causes differ: storm surge is produced mainly by weather systems, while tsunamis usually result from undersea earthquakes, landslides, or volcanic activity. Surge can flood low-lying coastal communities well before a hurricane’s strongest winds arrive.