Preparations are continuing in Texas ahead of the anticipated arrival of Edouard, the fifth tropical storm of this season.
The weather front strengthened late on Monday night as it churned across the Gulf of Mexico.
Forecasters say it is likely to hit the Texas and Louisiana coasts with near-hurricane force.
Late last month, Hurricane Dolly plowed into Texas with winds measuring more than 150 kph, dousing the area with tremendous rains and leaving more than 200,000 people without power.
It is feared Edouard could cause even more damage.
It has already forced several offshore oil operators to close down ports and evacuate staff from their platforms. But energy companies report little production slowdown.