Asian refiners are increasingly turning to sweet, or low-sulfur, light U.S. crude, amid falling production in Asia and as U.S. sanctions curb oil supply from Iran and Venezuela.
Forecasters said it would come dangerously close in the next 36 hours to Florida's east coast, where more than a million people have been ordered evacuated.
Singapore has been hit hard by the Sino-U.S. trade war, which has disrupted world supply chains in a blow to business investment and corporate profits.
MSCI's broadest index of Asia-Pacific shares outside Japan edged 0.1% lower, though it was up 0.6% for the week and on track to break a four-week losing streak.