Hurricane Idalia: Residents warned as supermoon could raise tides higher when storm hits Florida

After leaving parts of Florida battered and flooded, Hurricane Idalia is now moving over Georgia and South Carolina, ITV News US Correspondent Dan Rivers reports

A rare blue supermoon could raise tides above normal levels just as Hurricane Idalia hurtles towards Florida's west coast.

The moon will be closest to the Earth on Wednesday, the same day Category 4 Idalia is expected to make landfall with "catastrophic" 130mph winds.

While a supermoon can make for a spectacular backdrop in photos of landmarks around the world, its intensified gravitational pull also makes tides higher.

"I would say the timing is pretty bad for this one," said Brian Haines, the meteorologist in charge at the National Weather Service office in Charleston, South Carolina.

It’s expected to make tidal flooding worse not only in Florida, but in states such as Georgia and South Carolina, where Mr Haines’ office has been warning residents that parts of Charleston could be under water by Wednesday night.

How could the supermoon make the storm worse?

When the moon is full, the sun and the moon are pulling in the same direction, which has the effect of increasing tides above normal ranges, said Kerry Emanuel, professor emeritus of atmospheric science at the Massachusetts Institute of Technology.

The moon's gravitational pulls are stronger when it's closer to Earth, so the tides are even higher.

The storm surge, an abnormal rise of water or change in sea level generated by a storm, is often the greatest killer when hurricanes strike.

But storm surges taller than a person are a concern with any major hurricane - the tides and the influence of a supermoon can increase that.

The ocean water pouring onto land could be up to 15 feet along parts of Florida’s west coast, the National Hurricane Center projected.

"There’s a saying that you hide from the wind and run from the water, and hopefully people are heeding that advice,” said Brian Tang, associate professor of atmospheric science at University at Albany in New York.

Florida residents living in vulnerable coastal areas have been ordered to pack up and leave.

The National Weather Service in Tallahassee called Idalia “an unprecedented event” since no major hurricanes on record have ever passed through the Big Bend region of Florida.

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