Maritime weather: Special weather statements issued ahead of Thursday storm

Icicles from freezing rain hang from a bench in Fredericton on Tuesday, December 15, 2015. THE CANADIAN PRESS/Stephen MacGillivray

Weather statements

Environment Canada has issued special weather statements for southern New Brunswick, Prince Edward Island, and Nova Scotia. The statement is valid Thursday through Friday. It cautions of a mix of snow, ice pellets, freezing rain, and rain arriving in the region.

For New Brunswick, rain amounts of 25 to 50 mm is expected along the Fundy coast. There will be a risk of freezing rain for the Kennebecasis Valley and Petitcodiac River areas. High snow and ice pellets accumulations up to 25 cm is possible for southeastern New Brunswick.

For Nova Scotia, rain amounts of 25 to 50+ mm is expected, along with a risk of extensive freezing rain in northern and eastern areas of the province. Snow and ice pellets could accumulate up to 20 cm for northern regions.

For Prince Edward Island, rain amounts of 15 to 25 mm is expected. There will also be a risk of a period of freezing rain. Finally, a turn to snow and ice pellets could accumulate up to 25 cm.

Please take the time to check the details of the weather alerts in effect for your specific area. This system will bring highly varied, but impactful, weather conditions across the Maritime region.

Special weather statements issued for the Maritime provinces on Tuesday.

Arrival of heavy rain

Rain, heavy at times, develop across the province of Nova Scotia through the day on Thursday. The heavy rain could reach the southernmost areas of New Brunswick. The remainder of New Brunswick and Prince Edward Island can expect a mix of snow, ice pellets, and freezing rain during the day.

I have rain totals as high as 40 to 85 mm for the province of Nova Scotia. Rain totals reaching, or exceeding, 80 mm will come with an increased risk of localized flooding. A change from the rain to an extended period of freezing rain is possible Thursday evening and night. The freezing rain is likely to be most impactful in northern and interior areas of mainland Nova Scotia as well as across Cape Breton. Several hours of freezing rain will develop icy surfaces and could collect enough on tree branches to break them, which may result in power outages should they contact lines.

The system starts as heavy rain for the province of Nova Scotia. Some initial rain is possible for New Brunswick and Prince Edward Island before a turn to snow, ice pellets, and freezing rain.

Heavy snow and ice pellets

New Brunswick and Prince Edward Island are likely to see any initial rain turn to a mixture of snow and ice pellets during the day on Thursday. Accumulations of snow and ice pellets could total two to 10 cm for much of northern and western New Brunswick. Accumulations for southeastern New Brunswick and Prince Edward Island could total 10 to 25 cm as the mix continues into Thursday evening and night. Expect snow-covered and slippery road conditions to develop.

Snow and ice pellets continue to accumulate in southeastern New Brunswick and Prince Edward Island Thursday night. Rain in Nova Scotia will turn to snow, ice pellets, and freezing rain.

Northern areas of Nova Scotia could also switch to a period of heavy snow and ice pellets Thursday evening and night. The risk of accumulations from 10 to 20 cm in that province are highest for Cumberland, Colchester, Pictou, Antigonish, Inverness, Victoria, and Cape Breton counties. Lower, but still slick, accumulations of snow, ice pellets, and freezing rain are possible in the Atlantic coastal counties of Nova Scotia for Friday morning.

By Friday morning, even Atlantic coastal Nova Scotia should be cautious of slick surfaces as temperatures comes down enough to turn the rain over to a snow-ice mix there.

Wind gusty, but direction the issue

Wind gusts of 30 to 60 km/h are expected to accompany the wintry mix of weather. Initially out of the south for the province of Nova Scotia, it keeps milder air in place there, hence the rain start. A north-northeast wind will persist for New Brunswick and Prince Edward Island, bringing in colder air, turning the rain over to a mix of snow, ice pellets, and freezing rain.

The north-northeast wind then develops for Nova Scotia by Thursday afternoon. Colder air builds into that province, turning the rain over to freezing rain or a mix of snow and ice pellets. While not a flash freeze situation, the fall in temperatures brought on by the northerly wind is likely to be enough to bring surfaces down to the freezing mark across all of Nova Scotia by Friday morning.

Currently, it looks like the southeast of New Brunswick, northern areas of Nova Scotia, and Prince Edward Island have the greatest chance of seeing snow accumulate 10 to 25 cm.

Summary and updates

This is a complex, but impactful, round of weather setting up for Thursday into Friday. There will be parts of the region that have to contend with a heavy rain, and other areas an accumulating mix of snow, ice pellets, and freezing rain.

I fully expect to have to make significant updates to which areas of the Maritimes will see what. I also expect updates to the weather alerts posted by Environment Canada. I’ll have daily posts to the CTV News Atlantic website and more on CTV Atlantic News programming at 5 p.m., 6 p.m., and 11:30 p.m.