Hurricane Sally strengthens as it heads towards southern United States
Hurricane Sally churned slowly towards the coast of the southern US states of Alabama, Louisiana and Mississippi on Monday as it intensified into Category 2 storm.
At 2100 GMT, it was located 145 miles southeast of Biloxi, Mississippi, and heading in a west-northwesterly direction at six mph.
It was expected to make landfall late Tuesday or early Wednesday.
"Additional strengthening is forecast tonight and early Tuesday and Sally is expected to be a dangerous hurricane when it moves onshore," the NHC warned, using language that refers to a storm of Category 3 or higher at landfall.
Governor John Bel Edwards of Louisiana, which is still recovering from Hurricane Laura, which made landfall as a Category 4 storm, told residents to be prepared.
"Be smart and be safe," he tweeted.
The governors of Alabama and Mississippi both declared a state of emergency ahead of the approaching storm.
Mississippi Governor Tate Reeves said Hurricane Sally was expected to make landfall around Biloxi at 2:00 am (0600 GMT) on Wednesday.
"The storm surge projections continue to be worrisome with anywhere from five to eight feet (1.5 to 2.4 meters) of coastal surge," Reeves said.
"We are continuing to be very concerned about the amount of rainfall," he said, adding that some areas could be drenched in as much as 20 inches (50 cm) of rain.
Sally is one of five active tropical cyclones in the Atlantic Ocean.
The others are Hurricane Paulette, tropical storms Teddy and Vicky and tropical depression Rene.
According to meteorologists, the only other time there were five active tropical cyclones in the Atlantic at the same time was in September 1971.
Hurricane Paulette, a Category 2 storm, pounded the island of Bermuda on Monday with strong winds and heavy rains, according to the NHC.
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