Hurricane Danielle strengthened into a Category 4 storm on Friday as it churned over the Atlantic, the U.S. National Hurricane Center said.

Danielle, the first major hurricane of the season, was located some 545 miles southeast of Bermuda and was moving northwest at 12 miles per hour (19 km per hour).

It had top sustained winds of 135 mph. Any storm packing winds of at least 111 mph is ranked as “major” by the Miami-based hurricane center.

Computer models show Danielle tracking northwest and then in a more northerly direction before passing well east of Bermuda on Saturday night.