Millions of Florida residents are bracing for life-threatening storm surges, catastrophic winds and flooding as the hurricane racing towards its shores intensifies to a category four.

Hurricane Ian, which has already thrashed western Cuba, will reach Florida later on Wednesday.

According to the National Hurricane Center, NHC, the storm, with maximum sustained winds rising to near 155 miles per hour, is “rapidly intensifying”.

It is due to hit the Tampa Bay region.

The area is among the most vulnerable places in the US for severe flooding – and if Ian continues on its expected path, this would be the region’s first direct hit by a major hurricane since 1921.

Associate director of the International Hurricane Research Center, Erik Salna says it’s been around 100 years since Tampa had a direct hit.

He says they’ve just been lucky for a long time.

According to Mr. Salna low elevation, rising sea levels, and a large population increase the risk of a catastrophic tidal surge.

He says the Tampa area has all three.

He says if hit directly, the region could be “unrecognisable” in the next couple of days.

MSNBC’s Meteorologist Bill Karins at has the latest update.