A tropical storm watch is now in place from the New Orleans area to the Aucilla River in the Florida panhandle.
Heavy downpours were expected to begin lashing parts of Florida, Louisiana, Mississippi and Alabama on Sunday.
It is not organized enough yet to be a tropical storm, and is considered subtropical.
Florida, Alabama and MS declared states of emergency on Saturday as the storm threatened up to 12 inches of rain over the Memorial Day weekend, as well as tidal surges and damaging winds, according to Patrick Burke of the weather service's Weather Prediction Center in College Park, Maryland. "Rainfall amounts of 5 to 8 inches, and possibly locally up to double these amounts are possible in this area with this event", the NWS said.
The governors of Florida, Alabama and MS all declared states of emergency ahead of the storm. The tropical storm watch along the north-central Gulf Coast has been discontinued. Phil Bryant authorized the use of the National Guard, his office said in a statement. Winds will still be increasing into the afternoon with up to tropical storm gusts of 40 miles per hour along the coast.
Florida declares state of emergency ahead of storm Alberto
The forecast track of Subtropical Storm Alberto has shifted farther east, the National Hurricane Center said Saturday night. Water could reach up to 4 feet above ground in some areas if the peak surge occurs during high tide, the agency said on Facebook. A gradual strengthening was expected as the storm moves north.
An official from the National Weather Service warns that even after Subtropical Storm Alberto passes, there's still a risk for rip currents. In Cancun, local newspapers showed scenes of some streets flooded to mid-hubcap level.
According to a statement from the governor, the declaration covers all of the state's 67 counties, which are expected to see torrential rain and flooding after the storm makes landfall this weekend.
"Heavy rains and gusty winds continue to spread northward over Florida", it tweeted.More news: Trump to welcome ‘hostage’ from Venezuela
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