Tropical Storm Katia is now Hurricane Katia, but its impact on the United States, if any, remained unclear as it continued to strengthen on Thursday.

The National Hurricane Center upgraded Katia to a Category 1 hurricane early Thursday morning. The storm is about 1,700 miles southeast of Bermuda, moving northwest. By Tuesday, Sept. 6, it is expected to be about 600 miles south of Bermuda and about 500 miles east of the Bahamas, the Christian Science Monitor reported.

Forecasters said Katia could eventually strengthen into a major Category 3 hurricane, with winds over 110 miles per hour. However, the storm is still too far out to predict whether it will hit land at all, much less whether it will affect the United States or how bad it might be if it does.

Katia formed off the Cape Verde Islands in the eastern Atlantic Ocean on Tuesday, and it immediately got East Coast residents' attention as they coped with the severe flooding that Hurricane Irene brought to some areas over the weekend. Vermont and New Jersey were particularly hard-hit, and President Obama planned to visit New Jersey to assess the damage.

Katia is only the second hurricane of the 2011 Atlantic season. There have also been nine tropical storms and one tropical depression, and the National Hurricane Center said on Wednesday that a system in the Gulf of Mexico had a 70 percent chance of becoming a tropical depression in the next day or two.

If Hurricane Katia does hit the United States, it would be the second hurricane since 2008 to make landfall here. Hurricane Irene was the first.