Hurricane Florence: 'Catastrophic' storm surge could cause 3-metre-deep flooding

The storm surge caused by Hurricane Florence could cause "catastrophic" flooding for parts of North and South Carolina, despite the storm being downgraded as it neared land.

The threat comes as a video has been released from The Weather Channel in the US of the potential for the potentially destructive storm surge to soar about 2.7m tall.

The dramatic animation has been viewed more than 3.2m times on Twitter since it was posted on September 13.

The recreation shows the potentially life-threatening surge could rise above the height of cars and street signs and possibly into the first-floor levels of homes.

The National Hurricane Center said that freshwater flooding is expected over portions of the Carolinas as Hurricane Florence inches closer to the US East Coast.

The now Category 1 storm's intensity diminished as it neared land, with winds dropping to 135 km/h by nightfall.

But that, combined with the storm's slowing forward movement and heavy rains, had Governor Roy Cooper warning of an impending disaster.

As of 2 am local time, Florence was centered about 55 kilometers east of Wilmington, North Carolina.

Its forward movement increased slightly to 9 km/h as hurricane-force winds extended 150 kilometers from its center along with tropical-storm-force winds up to 315 kilometers.

Forecasters say the combination of a life-threatening storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline.

With AP.