After a relatively warm fall in the Maritime provinces, the reality of wintry weather is fast approaching with Environment Canada posting snowfall warnings for parts of the region.

Snowfall warnings are in effect for Nova Scotia and southern New Brunswick, and the snow is forecast to begin in southwestern New Brunswick on Wednesday morning. That's expected to spread east to Moncton by Wednesday afternoon.

Mark Palmer, a patroller with MRDC Operations Corporation in New Brunswick, said the precipitation must be monitored constantly during storms.

"We know that in the daytime you've got the sun helping you if the sun comes out after a snowstorm," he said.

"At night, you've got to really watch your temperatures because at night you can't put anything down if it's really cold."

A monitor on the side of Palmer's truck projects an infrared beam to the pavement, giving him an immediate surface temperature.

He said knowing when to put down salt, sand or brine, sometimes requires more than the machines can tell him.

"You get out with your boot and you twist and see if the roads slippery, frosty," Palmer said.

Environment Canada officials say the snow will be heavy at times.

The southern half of New Brunswick including Fredericton, Saint John and Moncton could see between 15 and 25 centimetres. The Fundy coastline could experience heavy rain.

In Nova Scotia, the mainland could see between 15 and 30 centimetres of snow on Wednesday afternoon and overnight, while the Atlantic coast may also see heavy rain.

Ken Robinson at O'Regan's Chevrolet in Halifax, said the company started getting calls in October about putting winter tires on cars.

"It's busy. We're booked out about a week right now," he said Tuesday.

"If you called today and wanted your tires put on, we're booking for Nov. 30 and Dec. 1 right now."