GRAY – Put away those sunglasses and keep the shovels handy.

A nor’easter is expected to blow into Maine on Monday. Snow is predicted to be heavy during the morning, but the total accumulation depends on if the storm comes up the coast or goes out to sea.

Either way, “It looks like certainly there’ll be enough to plow and shovel,” said National Weather Service Meteorologist Tom Berman.

“We’re having a problem pinning it down,” Berman said Saturday. “But we’re calling for snow to start after midnight Sunday night.”

Channel 13 meteorologist Craig Miller said there’s potential for 5 to 10 inches of snow, maybe more. The heaviest bands of snow will be across northern Massachusetts and southern New Hampshire, which could get a foot or more, he said Saturday.

The storm will have wind. “It will be the classic nor’easter. … There’s going to be significant snow. It will cause problems. We’ll have to break out the shovels.”

Never mind that it was 61 degrees on Tuesday, prompting people to shed their winter coats and snowbanks to melt. “The January thaw is over,” Miller said.

Principal to students: Do your homework, go to bed early

If the storm prompts another school closing Monday, it’ll be the third this winter.

“We had one the Thursday before the Christmas vacation, and on Wednesday at the end of vacation,” Vickie Gaylord, principal at Park Avenue Elementary School in Auburn, said Saturday.

Gaylord, who said she loves snow, advises students not to bank on no school.

She tells students to “be prepared for school. We don’t have a crystal ball” and can’t know for sure if school will be called off. “So go to bed early, be rested. Do your homework,” she said.

If it turns out there’s no school Monday, “Your homework will be done, you’ll be rested and ready to play in the snow,” the principal said. “Students should always be prepared for school.”

The thought of snow falling brings a smile to Gaylord’s face. “This is Maine. Snow is exciting,” she said. “Children love it.”

How a snow day is called

Auburn School Superintendent Tom Morrill on Saturday night divulged some of the science behind deciding to call a snow day.

The day before a storm, superintendents monitor the weather. “I’m always checking the National Weather Service” forecasts, he said.

He gets up at 4 a.m. to check forecasts, then goes outside to take a look. When his newspaper carrier drives up, the superintendent asks him what the roads are like. “He’ll say, ‘No problem’ or ‘No one should be out there,'” Morrill said.

The superintendent also checks with other school officials, police and highway crews for road conditions.

Around 5 a.m., he makes that special call to Lewiston School Superintendent Leon Levesque. The power brokers confer on what they’ll do. Using all the reports from meteorologists, police and highway personnel, they agree on whether to call a snow day.

They reach a decision together, Morrill said, which is why Lewiston will never be open and Auburn closed, or vice versa. Once they make the call, they split the media list of television and radio stations to contact to add the cities to the school closing lists. Both alert school personnel, which triggers a “schools closed today” notice on their school Web sites.

Superintendents are more likely to call school off when it’s snowing early in the morning, Morrill said. “The tricky ones are the storms where it snows all night and stops just before school opens.”

There’s no set number of inches of snow that triggers calling off school, Morrill said. If the snow is cold and dry and easy to move, a couple of inches may present little problem. But the same amount of heavier, wet snow that turns roads into skating rinks is “scary stuff” and means no school, Morrill said.

Some might think schools close more easily than years past. Morrill said that’s true.

Compared to a decade or two ago, “There’s more traffic. People are commuting longer distances,” Morrill said. “It’s a different ballgame. We have to be more cautious. People are traveling greater distances.”

On Tuesday, the forecast calls for clear skies, but that may not last.

Channel 13’s Miller said he’s watching another potential storm for Thursday.

For cancellations

To find out if there’s school Monday in Auburn, go to: http://www.auburnschl.edu/

To find out if there’s school Monday in Lewiston, go to: http://www.lewistonpublicschools.org/