Rain storm shatters records in N.S., called a “one-in-100 year event”

An official with Environment Canada says torrential rain in parts of Nova Scotia has shattered records.

A state of emergency was in effect Sunday after Halifax, East and West Hants, Lunenburg and Queens counties saw significant flooding and damage to infrastructure.

Meteorologist Bob Robichaud said 200mm of rain fell in many areas and some saw up to 250 millimetres (mm), most of which came down over several hours on Friday. There were unconfirmed reports of up to 300 mm falling in some areas.

“It certainly was a tremendous storm,” Robichaud said. “It was a record-shattering storm with the amount of rain we got in a short period of time.”

A rainfall warning had been issued on Friday calling for up to 80 mm of rain, and said a tropical stream of moisture was responsible for the forecast.

“When you have these tropical moisture feeds, there’s just so much of that moisture to be wrung out it creates very intense rainfall rates,” Robichaud explained. “We’ve seen set-ups like this before, but none in recent memory have stayed over the same area for an extended period of time which is what we saw on Friday.”

The storm brought rain to Nova Scotia in amounts not seen in more than 50 years. In 1971, Hurricane Beth dumped more than 270 mm on some areas and led to significant flooding.

“The one-in-100 year rainfall is 172 mm, so certainly with areas that have seen more than that it’s more than a one-in-100 year event, so a very rare event for sure.”

In a briefing on Saturday, Halifax Mayor Mike Savage said recent events in Nova Scotia, including Hurricane Fiona, recent wildfires and now flooding makes it clear climate change is having an impact in Nova Scotia.

Robichaud agrees.

“One of the stronger signals from climate change is that these events will be on the rise from climate change,” he explained. “The warmer the atmosphere, the more it can hold water. So in a warmer atmosphere, we’re going to get more of these types of events happen more frequently. That’s certainly what the data is showing.”

Environment Canada is forecasting a dry spell for the next few days in terms of precipitation, although it’s still expected to be humid into this week.