Environment Canada says the second named storm of the Atlantic hurricane season is expected to track northward and could at least be a factor for offshore waters on Wednesday and Thursday.
The national weather agency says it's too early to forecast the storm's impact on Atlantic Canada, but some land areas could be walloped with heavy rains.
"A few of the models are showing possible heavy rainfall for eastern parts of Nova Scotia and Newfoundland," an Environment Canada forecast said.
The near-hurricane-strength storm has sustained winds of 85 km/h in the Caribbean. Environment Canada says the storm is moving faster than a few days ago.
Bertha was moving over the Turks & Caicos Islands and the southeastern Bahamas on Sunday after emerging from the Dominican Republic, where overflowing rivers led to the temporary evacuation of dozens of families.
Chris Fogerty, manager of the Canadian Hurricane Centre, says it has been a fairly quiet hurricane season so far, except for Arthur.
He says that's typical because there has been a lot of activity in the Pacific Ocean and when that happens the Atlantic is generally quiet.