Map Shows Where Supermoon Could Spark King Tides in Florida

The largest full moon of the year is expected to generate flooding to parts of southern Florida this week, thanks to a phenomenon known as king tides.

The National Weather Service (NWS) has issued a coastal flood advisory for parts of Broward, Miami-Dade and Palm Beach counties ahead of the October supermoon, which should be visible in the Northern Hemisphere starting Wednesday night.

The service says there is a “moderate” risk of flooding in southeastern Florida from Wednesday night through Friday evening. Coastal flood advisories have also been issued near Jacksonville, Florida, along the Texas Gulf Coast and for parts of North Carolina’s coastline. A high rip current risk is also in effect for southeastern Florida through Sunday evening.

The advisories arrive as meteorologists warn of potential record-breaking high tides due to the supermoon, which may create conditions for king tides. The king tides occur when the sun, moon and Earth align, resulting in a stronger gravitational force that raises the ocean’s water levels.

A coastal flooding statement was also issued for parts of the Florida Keys by the NWS. The worst of flooding conditions will generally occur Wednesday into early next week, the service said in a post to its account on X, formerly Twitter.

“Flooding of low-lying parking lots, coastal roads, and parks may occur around periods of high tide,” the NWS added on X. “DO NOT park your vehicle in low-lying areas, as saltwater is corrosive and may damage vehicles.”

Residents under the flood advisory in southwestern Florida are urged to “allow extra time” while traveling in case some roads are closed. “Do not drive around barricades or through water of unknown depth,” the NWS said in its advisory. “Take the necessary actions to protect flood-prone property.”

During a high rip current risk, people are urged to swim near a lifeguard. “If caught in a rip current, relax and float,” the NWS advised. “Don’t swim against the current. If able, swim in a direction following the shoreline. If unable to escape, face the shore and call or wave for help.”

Senior NWS Miami meteorologist Robert Garcia told Newsweek earlier Wednesday that wind could make this week’s king tides even more severe.

“So the moon affects the tides, but then on top of that, a northeasterly wind is going to be funneling water towards the coast,” Garcia said. “It’s kind of like being in a bathtub and continuously shoving water with your hand in one direction. The water piles up.”