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A number of tornado warnings have been issued for Florida as the state braces itself to be battered by Hurricane Irma's full force.

But is it normal or just bad luck to be hit by both at the same time?

´óÏó´«Ã½ meteorologist Clive Mills-Hicks explains:

Hurricanes and tornadoes are typically thought of as separate phenomena, with tornadoes conjuring up images of the flat prairie and hurricanes associated with the warm, coastal tropics.

However, some tropical storms and hurricanes are capable of spinning up tornadoes, as Irma is expected to do. Hurricanes have all the necessary ingredients to create an environment perfect for tornado formations.

Image source, Reuters

First, hurricanes have within their circulation supercells, clusters of individual intense thunderstorm cells, which are rotating and well-organized. (These are typically the type of storm system that spin up twisters in the US plains.)

Second, hurricanes have the necessary very warm, moist air at the surface, which acts as their fuel and creates the instability essential for the supercells.

Finally, hurricanes always have wind shear, or an abrupt change in wind speed and direction with height. Shear like this sets up additional rotating motion on the horizontal, which can then flip into the vertical and generate tornadic spin. Most hurricanes that make landfall create tornadoes.

They’re restricted to land areas, instead of over water, because friction over the land slows down surface-level winds, creating even more wind shear.

The National Weather Service is warning Florida residents who find themselves in the eye of the storm not to be lulled into a false sense of security as the winds drop.

While it may appear the worst is over, the wind is likely to return at force, and without warning, from the other direction, the National Weather Service says.

Overnight the Fort Lauderdale Police Department posted a photograph of an officer and a police dog getting some sleep ahead of what is likely to be a busy day.

The area is already registering gusts of up to 70 mph (110km/h) as Hurricane Irma moves towards mainland Florida.

More than 565,000 homes and businesses are without electricity in Florida, according to the state's biggest power company.

Florida Power & Light - which is shutting down one of the two reactors at Turkey Point Nuclear Station, south of Miami - released the figures on its website on Sunday.

Meanwhile, Keys Energy Service said 29,000 had been cut off.

The National Weather Service confirmed its office was starting to experience 90mph (145km/h) gusts.

Reports say some wind measuring equipment is beginning to fail.

Despite the eye of the hurricane being focused on the state's south-west coast, there are very high winds and storm conditions reported as far as east as Miami Beach.

The City of Miami Beach has tweeted that authorities are no longer in a position to respond to emergency calls.

Image source, Paul Blake/´óÏó´«Ã½

The ´óÏó´«Ã½'s Paul Blake has been to the British Virgin Islands, to witness first-hand Hurricane Irma's trail of destruction.

Irma was still a category five storm when it first struck the Caribbean islands on Wednesday.

See more of Paul's pictures .

The US's southern-most naval air station has tweeted this footage, apparently filmed as they shelter inside one of their buildings.

The National Weather Service has issued a tornado warning for parts of Florida's east coast.

Speaking to NBC's Today Show on Saturday morning, Florida Governor Rick Scott described the storm surge as "really scary".

"We've prepared all week, although there's always something else you can do," he said.

Mike Theiss, who as a National Geographic photographer & storm chaser, has posted a video showing what looks like surge waters in the streets of Key West.

The National Hurricane Center has issued a storm surge warning for the next 36 hours in the Keys, among other locations across Florida.

CNN journalist Bill Weir is reporting from Key Largo, north-east of Key West.

David Ovalle, a reporter for the Miami Herald, is for as long as his signal allows.

The islands have been mostly without power for hours.

Irma has reached Florida, according to the US National Hurricane Center.

The eyewall is the hurricane's most destructive region.

The National Weather Service has warned people to act now to save their lives as Florida braces itself for winds of 130mph (210kph) and a storm surge which could reach 15ft (4.6m) in low lying areas.

Florida's journalists are keeping an eye on Irma as she makes her way towards the coast.

Steven Cejas, an executive producer at Miami's WSVN, shared this graphic showing what the storm looked like when she was still 30 miles out from Key West.

These photographs show why government officials have been so adamant residents of the Florida Keys should evacuate.

Image source, Getty Images

Image source, Getty Images

The string of islands extends for more than 100 miles, and is connected to the US mainland by a scenic highway.

It is feared the storm surges forecast could overwhelm the low-lying islands.