Schools in St. John's and other communities in eastern Newfoundland closed pre-emptively on Monday, as a weather system swept into the island.

Meteorologists, though, were warning of a much more powerful system that is expected to land later in the week.

CBC meteorologist Ryan Snoddon said the snow will fall continually through Monday and into Tuesday morning, leaving as much as 20 centimetres in parts of the Avalon Peninsula by the time the storm runs its course.

The Newfoundland and Labrador English School District closed numerous schools in the region for the morning, with an update expected later on whether afternoon classes will proceed.

Allison Sheppard, who works with Environment Canada's office in Gander, said the system will mean "some significant snow" for Avalon Peninsula residents.

"[It] looks like about 15 centimetres is going to start up this morning for the eastern part of the Avalon and that should taper off," she said. "We will get some flurries overnight, but the heaviest should taper off this evening."

Meanwhile, Snoddon described the storm that's poised to hit Newfoundland and Labrador on Wednesday and early Thursday as quite powerful.

He said the system will significantly exceed previous "weather bombs," which have involved a barometric pressure drop of 24 millibars (mb) in a 24-hour period.

"This storm looks set to be a double bomb, with models projecting a near-50-mb drop in 24 hours — a rare occurrence," said Snoddon.

He said that dramatic change will likely mean some very windy weather, with gusts topping 100 km/h in many areas, and with western Newfoundland and southern Labrador likely to bear the brunt of the snow. 

"It's going to be a really powerful, deep low," he said.