Heavy rain in New Brunswick is expected to continue overnight and into tomorrow morning, increasing flooding in parts of the province, says CBC meteorologist Kalin Mitchell.

"Much like it has been throughout the day, the rain is going to be heavy at times, particularly for central and southwestern parts of New Brunswick," he said.

"That should push some local totals in excess of 60 millimetres." Some communities could see upwards of 100 millimetres, he said.

By mid-Saturday, 30-40 millimetres had fallen in Miramichi, with the storm moving past Fredericton and heading into the southwestern corner of the province. St. Stephen had already seen almost 50 millimetres of rainfall.

flood farm

Some areas of the province have already seen 50 millimetres of rain from the system. (CBC)

The slow-moving weather system could bring isolated thundershowers along the Bay of Fundy coast. Strong wind gusts along the Fundy coast were expected to hit 50 to 70 kilometres per hour.

The heaviest of the rain is expected to end Sunday morning, leaving clouds and scattered showers in its wake, with winds and rainfall totals pretty much as originally forecasted, Mitchell said.

Flooding to worsen

The New Brunswick Emergency Measures Organization says flooding could worsen along some parts of the St. John River and its tributaries as the rain continues.

Fredericton, Jemseg and Sheffield-Lakeville Corner are expected to see flood water levels rise and flood conditions are expected to worsen in Maugerville. The Nashwaak River is also expected to hit the flood stage Sunday at Durham Bridge.

Increased flooding may impact some road infrastructure in downtown Fredericton, but not to the extent it has in other years, said EMO spokesman Paul Bradley.

flood houses

There was flooding in Maugerville on Saturday. (CBC)

"Just to put into context it's a long ways off from what 2008 was."

The EMO is asking people who live along waterways to remain alert.

Bradley said while the St. John River is a major concern, smaller tributaries can also present danger.

"One of the things about this amount of rainfall is smaller tributaries — you'll notice they fluctuate a lot faster. So some of them might have been down a little bit ... those things can come up very quickly," he said.

Stay away from the river

On Saturday morning, the Upper Kingsclear Fire Department and the RCMP responded to a ground search and rescue call looking for two individuals who went canoeing St. John River yesterday.

According to a statement from the RCMP, they were reported missing at 3:15 a.m. on Saturday after failing to return from picking fiddleheads.

They were found safe and sound, but Bradley warns against going too close to waterways.

"We strongly discourage people from getting close to the rivers at this point. The banks of waterways are unstable, te water's flowing very fast, it's cold, it could be carrying debris," said Bradley.