A slow-moving weather system is expected to dump approximately 50 millimetres of rain in parts of Nova Scotia on Tuesday.

Jim Abraham, a CBC meteorologist, said Yarmouth reported 30 millimetres of rain overnight and Briar Island reported 37 millimetres.

"It's moving rather slowly eastward, which is not good because the precipitation intensity will be significant while it's over us," he said Tuesday.

"The total amounts will total in excess of 50 millimetres for western Nova Scotia. I wouldn't be surprised to see some areas getting a total of 75 millimetres given the intensity. There could be some thunderstorms embedded in this."

Environment Canada issued rainfall warnings for much of southern, western and central Nova Scotia and said heavy clouds have already dumped a significant amount of rain over the area. Those warning started to clear by 9:30 a.m.

Total rainfall amounts, including what has already fallen, could exceed 60 millimetres in some areas.

"That line of heavy precipitation will continue eastward, probably not reaching the Canso Causeway until suppertime or into the early evening before it gets into Cape Breton Island. The back edge, however, will start tapering off so I would say Yarmouth will start tapering off to showers later this morning," said Abraham.

"Certainly the easing off of the precipitation will gradually take place over western Nova Scotia during the latter part of the morning into the early afternoon and the back edge probably not reaching Halifax until suppertime so it's going to be, for the central part of Nova Scotia including Halifax, a rainy day."