Nor’easter could bring more heavy snow, high wind to the Maritimes

Nova Scotia remains at highest risk of heavy snow and high wind from a Nor’easter moving up off the U.S. eastern seaboard Sunday into Monday.

A Nor’easter developing on the eastern seaboard of the U.S. could bring heavy snow and high winds to parts of the Maritimes.

A Special Weather Statement was issued for Nova Scotia at 3:20 p.m. on Thursday. The statement said the storm could bring 15 to 30 cm of snow and wind gusts that could reach 60 to 80 km/h from Sunday afternoon through Monday evening, making travel conditions slow and hazardous.

The statement said water levels could be higher than normal and the province could experience large crashing waves during high tides on Monday.

The latest

Computer forecasts show a lot of variance for the location of snowfall and strong wind. This is common for rapidly developing weather systems like Nor’easters. Forecast models are almost always more accurate when the storm system has already developed. In this case, that happened Friday as low pressure shifts from the Gulf of Mexico to the coastline of the Carolinas.

Forecast models agree the system will undergo explosive cyclogenesis -- commonly referred to as a “weather bomb” -- with the central pressure dropping more than 24 millibars in 24 hours. The storm system will then move north and east of Cape Cod and become a concern for the Maritimes Sunday morning.

Models vary when trying pinpoint the storm’s path. Many place the centre near Sable Island, which is a good “benchmark” position for heavy snow and strong wind events in Nova Scotia. Other models place the storm east of Sable Island, potentially reducing the impact on the Maritimes, but I’d consider that an unlikely scenario as of Thursday afternoon.

It is recommended people monitor the forecast for Sunday and Monday and prepare accordingly.

Areas of risk

There is high risk of heavy snow and high wind for Nova Scotia and eastern Prince Edward Island and a moderate risk for the southeastern and Fundy coastal area of New Brunswick and western Prince Edward Island.

A low risk of heavy snow and high wind is forecast for central New Brunswick and a much lower risk for northern New Brunswick.

A storm of this nature

There are likely to be significant differences between the weather from this system and the ones that impacted the Maritimes over the past two weeks. The snow is unlikely to be all powder or heavy and wet - mostly a “standard” snow falling for a shorter duration. This isn’t another 48-hour event like we had at the start of last week. The heaviest snow will likely fall within a 12-to-24-hour period.

There is higher wind potential for the upcoming storm. Areas exposed to stronger wind have an increased risk of utility outages. The greater risk of snow combined with wind could contribute to more periods of reduced visibility or “white out” conditions.

I’ll provide more updates at CTV Atlantic on Friday and through the weekend.