A messy mix of snowfall and cold rain has caused power outages, school closures and flight cancellations Wednesday in the Maritimes.

New Brunswick was the hardest hit by the storm that hit overnight, with NB Power reporting over about 40,000 customers waking up without electricity.

The largest concentration of outages are in Moncton and in Central York and Sunbury counties.

The utility says it has crews out making repairs across southern New Brunswick.

There were also early morning outages reported in Nova Scotia's Pictou County.

By Wednesday morning, Prince Edward Island also was seeing a significant accumulation of snow, with schools closing and flights into Charlottetown delayed.

The RCMP on the Island issued a warning about slippery road conditions and some health care clinics were closing for the day.

Environment Canada had weather alerts in place for much of New Brunswick, where snow accumulations could reach 25 centimetres in some communities by Thursday, while P.E.I. was also expecting some wet snow.

Another low pressure system is expected to move through the province through Wednesday night, continuing the messy weather.

Parents in Nova Scotia and New Brunswick were being advised to check school board notifications, as many schools were announcing cancellations and some buses aren't running due to slick roads.