August 28, 2008 Gustav grows near Jamaica; New Orleans watches with nervous eye Play video

(NECN/ABC) - Gustav has already caused damage as it came ashore in Haiti and the Dominican Republic, with wind speeds of up to 90 miles an hour. 22 people at least have been killed.

Roads were blocked by falling trees. Rivers burst their banks and streets were flooded by the prodigious rainfall.

Now it did lose some speed as it passed over Haiti. It was downgraded to a tropical storm.

But now that it's moving back out over open water between here in Jamaica and Cuba out there, it's likely to pick up more speed. Forecasters even predict it could even reach a category three hurricane or stronger.

In advance, they are evacuating oil rigs throughout the Gulf of Mexico. And indeed the oil prices have gone way up in anticipation of some disruption of supplies.

Now it's unclear yet where it will actually make landfall in the United States. But a lot of the models are pointing right towards New Orleans.

And of course, this comes almost exactly three years to the day after the devastation of Hurricane Katrina.

In advance of the potential landfall there, authorities in Louisiana are already drawing up detailed evacuation plans. They don't want to get caught out like they did last time.

But until forecasters have an accurate picture of exactly where the storm is going to hit, all the anxious residents along the Gulf Coast can do is watch and wait.

Terry McCarthy, ABC News, Montego Bay, Jamaica.