Tropical Storm Ian is expected to be a major hurricane in the eastern Gulf of Mexico during the middle of this week, the U.S. National Hurricane Center (NHC) said on Sunday.

There is a risk of dangerous storm surge, hurricane-force winds, and heavy rainfall along the west coast of Florida and the Florida Panhandle by the middle of this week, according to an NHC update.

The forecaster urged residents in Florida to ensure that they have a hurricane plan in place.

Tropical Storm Ian was located about 700 km southeast of the western tip of Cuba, with maximum sustained winds of 95 km per hour, on Sunday afternoon.

Hurricanes rated Category 3 and higher are known as major hurricanes that can cause devastating to catastrophic wind damage and significant loss of life simply due to the strength of their winds.

U.S. President Joe Biden issued an emergency declaration for Florida on Saturday as Ian was intensifying in the Caribbean.

The storm system comes a week after Hurricane Fiona hit Puerto Rico, bringing heavy rainfall and flash flooding to the U.S. territory while cutting power to the entire islands.

There are more than 600,000 customers still out of power in Puerto Rico, as of Sunday night, according to an online tracker.

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