Category 5 Hurricane Maria's maximum sustained winds have increased to 280 km/h.
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Source: 1 NEWS
The National Hurricane Center in Miami says an Air Force Reserve hurricane hunter plane took the reading today as the storm was about 115 kilometres southeast of St. Croix.
Maria is moving west-northwest at 17 km/h, and is expected to pass near the US Virgin Islands on Tuesday night (local time) and hit Puerto Rico later today.
A hurricane warning was in effect for Puerto Rico and the US and British Virgin Islands, as well as St. Kitts, Nevis, and Montserrat and portions of the Dominican Republic.
Hurricane center forecasters say it "now appears likely" that Maria will still be at category 5 intensity when it moves over the US Virgin Islands and Puerto Rico.
The centre of the hurricane was forecast to move near or over the US Virgin Island of St. Croix and Puerto Rico, bringing with it "life-threatening" flooding from rain and storm surge.