FREDERICTON -- A storm that brought a mix of heavy rain, snow and wind gusts to the Maritimes on Wednesday resulted in power outages and made for treacherous road conditions that police say are to blame for a crash in New Brunswick that killed three people.

The RCMP say they believe the poor weather contributed to a head-on collision between a car and tractor-trailer near Fredericton that left two 23-year-old men and a woman, 41, dead.

Schools in the province were closed as a result of the storm, which is expected to dump up to 40 centimetres of snow on northeastern parts of the province by Thursday morning.

Environment Canada said more than 80 millimetres of rain fell on the island of Grand Manan by midday Wednesday and that amount could double before the storm passes through.

Flooding is a concern as the ground is frozen and unable to absorb the rainfall, said Paul Bradley, a spokesman for New Brunswick's Emergency Measures Organization.

"We are asking people to remain on alert and vigilant in protecting their homes and belongings, especially in areas close to water or people who have experienced flooding in the past," Bradley said.

Meghan Gerrish, a spokeswoman for NB Power, said most of the province's power outages were in the Woodstock and Miramichi areas and crews were dispatched to restore electricity.

"We will move crews around as required," she said.

Flood warnings were issued for the Nashwaak River north of Fredericton and Canaan River north of Petitcodiac, where officials said there is a risk of ice jams.

In Halifax, a portion of the Bedford Highway was closed due to flooding and drivers in the city were advised to use caution as a result of water on roads.

Drivers in Prince Edward Island were told to be careful as the rain caused flooding and culvert washouts, forcing some roads to be shut down.