Forecasters say Hurricane Bertha has weakened to a Category 1 storm.

As of 5 p.m. EDT Tuesday, its center was 620 miles east-northeast of the northern Leeward Islands and 900 miles southeast of Bermuda .

Maximum sustained winds decreased to 85 mph. The storm is to continue weakening over the next couple of days. The Atlantic season's first hurricane is headed northwest at about 12 mph.

Bertha is expected to continue heading toward Bermuda . Large swells and high surfs could affect portions of Bermuda late Wednesday.

It is unknown if or when the hurricane will make landfall.

Click here for maps, forecasts and satellite images at the National Hurricane Center