Tropical Storm Arthur threatens life-threatening flooding across U.S. Gulf Coast and Southeast

The first storm of the Atlantic Hurricane Season has formed. Tropical Storm Arthur is about 35 kilometres north-northwest of Matagorda, Texas.

Arthur is expected to bring life-threatening flash flooding to parts of the southeastern United States as it moves inland over Texas, according to the U.S. National Hurricane Center.

The storm has maximum sustained winds of 75 km/h, with higher gusts, and is expected to weaken as it moves farther inland. Arthur could dissipate by late Wednesday night or early Thursday.

Despite the weakening trend, officials warned that heavy rainfall poses the greatest threat. The storm is forecast to produce widespread rainfall totals of 125 to 250 millimetres, with isolated amounts approaching 500 millimetres through early Friday.

The heaviest rain is expected from the Texas Gulf Coast eastward through Louisiana, Mississippi and Alabama, extending into western Georgia and the Florida Panhandle.

Storm surge flooding is also possible along parts of the Gulf Coast. Water levels of 0.3 to 0.9 metres above normally dry ground are forecast from Matagorda, Texas, to the mouth of the Mississippi River in Louisiana, particularly near and east of the storm's landfall area.

A few tornadoes could develop late Wednesday in southeastern Louisiana and southern Mississippi, with the threat shifting into parts of Alabama, Georgia and the Florida Panhandle on Thursday.