Storm surge rides on top of whatever the sea level already is, and the moon’s pull on the tides helps set that baseline height. A new or full moon at perigee — a supermoon — stacks the highest tides on top of the surge, while a first- or last-quarter moon at apogee does the opposite. A separate 18.6-year lunar wobble will start amplifying tides again in the mid-2030s, just as rising sea levels push U.S. coastal flooding higher.