Cuba is being hit by a storm heading north to the US. Photo / AP
Florida, Alabama and Mississippi launched emergency preparations ahead of the arrival of Subtropical Storm Alberto, a slow-moving system expected to cause wet misery across the eastern US Gulf Coast.
Cuba was being pounded by rain along its western coast, raising the threat of flash floods and mudslides.
The National Hurricane Centre in Miami said the island's rain totals could reach 25-38cm — and even 65cm in isolated areas.
Heavy downpours were expected to begin lashing parts of Florida, Louisiana, Mississippi and Alabama tomorrow.
Tropical storm warnings have been issued for parts of Florida and Alabama, saying tropical storm conditions are possible there by tomorrow night NZT.
The governors of Florida, Alabama and Mississippi all declared states of emergency ahead of the storm.
About 13-25cm of rain are possible along affected areas in eastern Louisiana, Mississippi, Alabama, western Tennessee and the western Florida Panhandle. Isolated areas could see as much as 38cm.
Under overcast skies and occasional drizzle, several Gulfport, Mississippi, residents lined up to fill sandbags to block any encroaching floodwater expected as a result of Alberto.
Tommy Whitlock said sandbagging has become a usual event in his life since he lives next to a creek.
"I'm doing this because every time we have a hard rain, it floods at my house," Whitlock said. "We get water from other neighbourhoods, and water can get up to a foot deep in some places."
Eddy Warner, a retired consultant for a construction company, filled bags while waiting for his nephew to come help transport them home to protect his garage.
"I'm 65 years old and too old to be doing this," he said, laughing.
Alberto — the first named storm of the 2018 hurricane season that officially starts on June 1 — is expected to strengthen until it reaches the northern Gulf Coast, likely on Tuesday.
The NWS said waves as high as 5.5m could pound the popular Gulf beaches in Baldwin County, Alabama, and northwestern Florida. A high surf warning was in effect.
A subtropical storm like Alberto has a less defined and cooler centre than a tropical storm, and its strongest winds are found farther from its centre. Subtropical storms can develop into tropical storms, which in turn can strengthen into hurricanes.