Hurricane Isaac strengthened slightly and turned north Sunday in the Atlantic, forecasters said, and a tropical storm watch was issued for southeastern Newfoundland.

At 11 a.m. EDT, Isaac had top sustained winds near 80 mph, up from 75 mph on Saturday, when it became the fifth hurricane of the Atlantic season.

The ninth named storm of the Atlantic hurricane season was centered about 295 miles east-northeast of Bermuda and moving north near 13 mph. A turn to the north-northeast and an increase in forward speed was expected in the next day, the National Hurricane Center in Miami said. The storm also was forecast to begin weakening in the next 24 hours.

The Canadian Meteorological Service issued a tropical storm watch for Newfoundland's Avalon Peninsula, including the cities of Cape Race and St. Johns.

Hurricane-force winds extend 25 miles from Isaac's center, while tropical storm-force winds extend up to 115 miles from it.

The Atlantic hurricane season began June 1 and ends Nov. 30.

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