A tropical storm swirling in the US Gulf is expected to bring heavy rainfall and a "life-threatening storm surge" to the south-east of the country, according to the National Hurricane Center (NHC). Tropical Storm Bertha was located about 105 miles (165km) south of Panama City, Florida, carrying windspeeds of 40mph (65 km/h) on Monday. The storm could trigger flooding and storm surges in Alabama, Florida, Louisiana and Mississippi as it drifts west towards Texas. "A tropical storm watch is in effect for Ochlockonee River, Florida, westward to the Jefferson/Plaquemines Parish border in Louisiana," forecasters said. This is only the second named storm of the season, after Tropical Storm Arthur brought some flooding to the US last month.