MIAMI (AP) — Hurricane Gabrielle formed Sunday in the open Atlantic southeast of Bermuda, while Tropical Storm Narda emerged well off southern Mexico’s Pacific coast.

The Miami-based National Hurricane Center said Gabrielle became a Category 1 hurricane after its top sustained winds rose to 75 mph (120 kph). Gabrielle was centered some 320 miles (515 kilometers) southeast of Bermuda and was moving to the north-northwest at 10 mph (17 kph).

The hurricane center said Gabrielle could become a major hurricane in the early part of this week as it is expected to undergo steady to rapid intensification over the next day or so. On the current forecast track, Gabrielle was expected to pass east of Bermuda on Monday.

A hurricane hunter aircraft found the storm at hurricane strength and moving on a more north-northwest track. But the center said a more northerly course was expected Monday. No coastal watches or warnings are in effect, but meteorologists urged interests in Bermuda to keep close watch.

Large ocean swells kicked up by Gabrielle are impacting Bermuda and are expected to reach the Eastern Seaboard from North Carolina northward into Atlantic Canada over the coming days.

In the Pacific, Narda emerged well offshore of Mexico on Sunday afternoon and posed no threat to land.

The hurricane center said Narda had top sustained winds of about 40 mph (65 kph) and was positioned about 240 miles (386 kilometers) south-southeast of Zihuatanejo, Mexico, while moving to the northwest at 10 mph (17 kph). The center says Narda could become a hurricane while heading further offshore.