The usual reason for coastal flooding is low atmospheric pressure. We might not even think of it but air has mass and it is usually weighing down on the oceans and keeping it compressed. The air when there is low pressure is less dense so there is less weight pushing down on the seas. This causes the previously compressed water to expand and that is why the sea level rises slightly. This is most notable during times of hurricanes as they are very large low pressure systems.
MCMLXXXII t1_j1hwuqq wrote
Reply to Hudson overflowing. Stay safe! by Desi_techy_girl
The usual reason for coastal flooding is low atmospheric pressure. We might not even think of it but air has mass and it is usually weighing down on the oceans and keeping it compressed. The air when there is low pressure is less dense so there is less weight pushing down on the seas. This causes the previously compressed water to expand and that is why the sea level rises slightly. This is most notable during times of hurricanes as they are very large low pressure systems.