Environment Canada is warning of rip currents, rapidly changing water levels and heavy rainfall in parts of Atlantic Canada as Hurricane Gert glances the region Thursday.

The national weather forecaster said while Gert would not have a direct impact on the Atlantic provinces, long-period swells are expected on the southern coasts of Nova Scotia and Newfoundland with waves reaching up to four metres in some areas.

"With the combination of the higher waves and swells associated with Gert, it may result in some minor flooding," said meteorologist Linda Libby.

"We're not looking at widespread, but we are looking at a possibility of pushing it past highest water levels."

High surf at Lawrencetown Beach, Nova Scotia

Surf was higher than usual along the Atlantic coast of Nova Scotia. (Paul Palmeter/CBC)

Libby said dangerous rip currents are possible, so residents are warned to be cautious while swimming.

Why take the risk?

"Obviously we want to keep everyone safe and secure here, so why take the risk if we're going to get these swells and enhanced waves occurring on the backside of Gert," she said.

Some moisture from the storm was expected to feed into an approaching non-tropical weather system near eastern Newfoundland, bringing up to 50 millimetres of rain to some areas of that province and up to 100 millimetres in the Northern Peninsula.

Gert was also expected to cause a series of rapid changes in water levels in harbours and inlets in eastern Newfoundland for a few hours late Thursday afternoon or evening.

Libby said conditions from Gert are expected to gradually diminish Thursday into Friday from west to east.