Cuban authorities said they had begun restoring power to the eastern half of the island on Thursday, a day after Hurricane Rafael knocked out the country's electrical grid, leaving 10 million people in the dark.

The hurricane center cautioned there is "larger-than-normal uncertainty regarding Rafael's intensity later in the forecast period."

Hurricane Rafael has pushed into the Gulf of Mexico after plowing across western Cuba as a Category 3 hurricane with winds so powerful it knocked out the entire country’s power grid.