Thousands have been evacuated from the coast of Florida as the region braces for subtropical storm Alberto that has picked up pace ahead of the official hurricane season.
Anticipated to make landfall on Monday, Alberto is the first storm ahead of this year's Atlantic hurricane season, which formally starts on June 1, BBC reported.
It will bring heavy rain and winds of 100 kmh across southern states, the US National Hurricane Center said.
It was centered about 185 km southwest of Florida's Panama City, at 6:00 GMT on Monday.
Alberto had picked up strength as it headed north through the Gulf of Mexico, bringing with it the warning of life-threatening inundation, said the Miami-based hurricane center.
It is forecast to drop as much as 30 cm of rain across Mississippi to western Georgia and to bring storm swells of about 60-120 cm to low-lying areas.
Alberto comes during the Memorial Day weekend, and was expected to affect travel on Monday, when many people will return from their holidays.
It is the first named storm of the season, with 21 other names still to be used, including Beryl, Ernesto, Kirk, Nadine and Rafael.
Last year, a number of deadly hurricanes hit the US and Caribbean. Puerto Rico, for example, is still struggling with its recovery efforts following major infrastructure damage from Hurricane Maria in October.
