Storm Barry has made landfall in Louisiana, where officials have warned of potentially life-threatening floods.
The storm reached hurricane-strength as it neared system, but has now weakened to a storm packing sustained wind speeds of 70mph.
The system is crawling north-west at a speed of just 6mph, dumping heavy rainfall as it tracks inland.
The worst of the storm is expected to hit an area west of New Orleans, and affect the wider region.
Thousands have been evacuated from areas most at risk of flooding.
About 100,000 households are already without power.