HOUSTON (AP) — The National Hurricane Center says heavy rain from Harvey is expected to worsen flooding in Southeast Texas and southwestern Louisiana.

The center says in its 4 a.m. CDT advisory that flooded roadways continue to make travel difficult and advises people to take shelter.

The center of the storm was marked 135 miles (220 kilometers) south-southwest of Port Arthur, Texas, and was moving east at 3 mph (4.8 kph) with sustained winds of up to 45 mph (72 kph).

The storm was expected to make a slow turn to the northeast on Tuesday, placing the center just off the middle and upper Texas Gulf coast through Tuesday night before moving inland. Harvey is expected to produce 10 to 20 additional inches or rain over the upper Texas coast and southwestern Louisiana through Thursday, with isolated storm totals maybe reaching 50 inches (130 centimeters) over the Houston-Galveston area and the upper Texas coast.