Tropical Storm Karen lost strength and became a tropical depression off the US coast near Louisiana, the National Hurricane Center reported.
All tropical storm warnings were discontinued, but Karen is still expected to bring heavy rain and some coastal flooding as it moves east and rakes the Gulf Coast from central Louisiana to the Florida panhandle late Sunday and Monday.
At 0300 GMT Sunday the center of Karen was stationary, parked some 295 kilometers (183 miles) southwest of the mouth of the Mississippi river and packing maximum sustained winds of 55 kilometers per hour.
Karen is forecast to drop up to 7.6 centimeters (three inches) of rain over the central Gulf Coast and southeastern US region through late Monday.
Florida Governor Rick Scott said Saturday that 12 counties were under a local state of emergency and urged residents not to become complacent because the storm was weakening.
"Communities along the panhandle are expected to experience heavy rains, and storm surges are predicted for our coastal regions," Scott said in a statement.
Oil prices rose Friday on falling production as companies evacuated staff from sensitive refining and production areas along the Gulf Coast.