Devon Bryan, foreground, rides a wave produced by tropical storm Cristobal while surfing Sunday at North Topsail Beach, N.C. (Don Bryan/Jacksonville Daily News/Associated Press)

Tropical storm Cristobal is expected to pass south of Nova Scotia on Tuesday, dumping as much as 100 millimetres of rain on parts of the province as its power begins to ebb, federal meteorologists said Monday evening.

Cristobal's maximum wind speed, now 111 kilometres an hour, is expected to fall to "post-tropical" levels of 83 to 93 km/h on Wednesday and 65 to 74 km/h on Thursday.

Rainfall warnings were issued for most regions of mainland Nova Scotia, but no tropical storm watch was planned because the strongest winds were expected to remain offshore, the Canadian Hurricane Centre said in a statement issued at 9 p.m AT.

That might not reassure seafarers, however.

Cristobal's centre was expected to move over Georges Bank, a fishing ground shared by Canada and the United States, around midday on Tuesday. Gales were forecast for offshore waters south of Nova Scotia, suggesting winds of 65 to100 km/h.

Cristobal, which formed off the coast of the Carolinas, was still south of Cape Cod, Mass., as of Monday evening.

CBC meteorologist Peter Coade said it may bring localized flooding as it moves north.

"The good thing about it is we're not anticipating hurricane-force winds. It is mostly going to be a rain event for most of Nova Scotia," he said.