Sudden, temporary rise of sea level primarily due to winds but also caused by atmospheric (barometric) pressure reduction, resulting in piled-up water against the coast, which is the primary cause of coastal flooding during a storm.
NOAA has an "Extra-Tropical Storm Surge" website that predicts tides 3 days out. To use this, find the tide gauge near you on the appropriate regional map and click on it.
The video below was provided by NOAA. It explains the dangers of a storm surge during hurricanes.