ST. PETERSBURG, Fla. -- Still days away from a possible U.S. impact, dangerous Hurricane Irma bears continuous watching as it churns toward the Caribbean islands.

The National Hurricane Center's 11 p.m. Tuesday, Sept. 5, advisory pegs Irma as an extremely dangerous 185-mph storm -- a Category 5 on the Saffir-Simpson hurricane wind scale. It is moving west-northwest at 15 mph and was located 50 miles east of Antigua.

Its minimum central pressure is 916 mb.

"Irma is a potentially catastrophic category 5 hurricane and will bring life-threatening wind, storm surge, and rainfall hazards to portions of the northeastern Leeward Islands beginning later today and the Virgin Islands and Puerto Rico beginning tomorrow," the hurricane center writes.

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Hurricane warnings are in effect for many of the islands, including Antigua, Barbuda, the U.S. Virgin Islands and Puerto Rico. A hurricane watch is posted for the Bahamas, the Dominican Republic and others. Visit the National Hurricane Center's website for the latest.

Photos: Irma at 185 mph -- a dangerous Category 5 storm

Irma and its westward movement means the storm always is getting closer to the U.S. but the question is: where will it end up?

The official track -- sometimes called the "cone of uncertainty" -- includes southern Florida from Key West to Miami and Port Charlotte. This is where the "uncertainty" comes in: it is next to impossible to say where Irma or any storm for that matter ends up in excess of four or five days or more.

The "cone" at day five showing Irma's track has the storm anywhere south of Cuba to the Bahamas or entering the Gulf of Mexico.

There is good confidence the storm will be a major, Category 3 or greater, storm as it makes its approach. There is less certainty about where it'll go later this week.

Given this, there is time to prepare -- and that time is now.

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