The first hurricane of the 2008 Atlantic storm season was almost stationary near Bermuda Saturday, but was strong enough to spark tropical storm warnings on the island.

Hurricane Bertha was about 320 kilometres southeast of Bermuda early in the day.

Bertha's maximum sustained winds were clocked at 137 km/h, making it a Category One hurricane.

The storm was expected to start lurching forward on a northwestern track later in the day, moving at four km/h, the U.S. National Hurricane Center in Miami said.

Forecasters said Bermuda is likely to receive at least 50 millimetres of rain in the next two days.