More thaw and freeze ahead in the Maritimes this week

A pedestrian tries to shield herself from heavy wind and rain in Halifax on Friday, December 23, 2022. THE CANADIAN PRESS/Darren Calabrese

Weekend rain summary

Following a weekend that saw heavy rain transition to a flash freeze, a similar weather situation is ahead for the Maritimes later this week.

The heaviest rain fell across Nova Scotia and Prince Edward Island. Fairly widespread amounts of 30 to 60 mm was reported in those areas. Personal weather stations in Victoria County, Cape Breton, reported some totals of 70 to 85 mm of rain. The rain, along with snow/ice melt and blocked drainage, created some instances of localized flooding.

The quick change to a northerly wind behind the rain brought temperatures back down below freezing in just a matter of hours and remaining standing water turned to ice. A turn back to snow for southeastern New Brunswick, northern Nova Scotia, and P.E.I. brought 5 to 15 cm of snow.

CoCoRaHS volunteers and Environment Canada-monitored weather station reports for the weekend rain.

Mid-week repeat

The weather ahead of us Wednesday into Thursday bares some similarity to this past weekend. A strong low-pressure system is expected to move up the St. Lawrence River Valley. The storm first brings a warm up and rain on Wednesday. Then on Thursday, as a cold front comes through, the rain turns to a period of snow and temperatures fall quickly back below freezing in a northwest wind.

With a storm track to our west, the next system initially comes in with mild temperatures, rain, and a gusty southerly wind.

The rain could potential be very heavy for parts of the Maritimes. Guidance for the storm has possible rain totals of 40 to 70 mm for southern New Brunswick and western Nova Scotia. The same guidance indicates that pockets of rain near or over 100 mm is also possible around the Bay of Fundy coastline in New Brunswick. That amount of rain at this time of the year does come with an increased risk of localized flooding. Other areas of the Maritimes are currently indicating rain amounts of less than 40 mm.

Areas of heavy rain are indicated in the south of New Brunswick and the west of Nova Scotia.

There is a higher potential for severe wind with this storm. Southern New Brunswick, Nova Scotia, and P.E.I. have indicated gusts from the south that could reach 90+ km/h late Wednesday into early Thursday morning. Gusts of 90+ km/h are the criteria for wind warnings to be issued.

A strong southerly wind could reach gusts of 90+ km/h late Wednesday into early Thursday for parts of the Maritimes.

Weather alerts

As of Monday afternoon, there are no weather alerts for the Maritimes. In Quebec, where the storm reaches earlier, a special weather statement is in effect cautioning of a risk of localized flooding as a result of the rain and mild temperatures. The statement also mentions that behind the rain “temperatures will drop sharply, rapidly freezing water on the ground. Roads could quickly become slippery, making travel difficult.”

A hazardous weather outlook has been issued by the National Weather Service in Maine. That state is also expecting a significant rainfall followed by a possible flash freeze Wednesday into early Thursday morning.

I’ll have updates, timelines, and regional weather conditions on CTV New Atlantic at 5 p.m., 6 p.m., and 11:30 p.m.