Subzero temperatures are on Maine’s doorstep, with wind chills expected to make conditions even more dangerous.

Michael Clair, a meteorologist with the National Weather Service in Gray, said that is because of a “pretty big arctic air mass” entering Maine via Canada.

“It’s going to be a combination of cold and wind, especially Friday night and Saturday morning,” Clair said.

Temperatures will drop below zero across the state, Clair said, with negative single digits expected in the south and along the coast, and northern Maine seeing temperatures dip below negative 10.

But it will likely feel even colder than that.

“Wind chills could be in the minus-teens to minus-20s across most of the area,” Clair said. “Even in the negative-30s in the north.”

Portland plans to open its warming center, at 166 Riverside Industrial Parkway, on Friday, Saturday and Sunday nights, according to city spokesperson Jessica Grondin.

Mainers will begin to feel relief from the arctic cold on Sunday and, that night, a lengthy snowstorm is expected to begin.

Clair said it’s too early to predict totals, but he wouldn’t be surprised to see at least 6 inches of snow across a large portion of the state. He said Thursday that the weather service expects snow to be heaviest in the south and along Maine’s coastline.

“That’s where we’re most confident right now,” Clair said.

The storm is expected to arrive late Sunday night and roll through Monday.

“It’s going to be a pretty long-duration event,” the meteorologist said.

FROSTBITE RISK

The Maine Emergency Management Agency is urging Mainers to avoid prolonged outdoor activities, dress in layers to prevent frostbite, not leave pets outside, check on elderly or sick neighbors, and provide shelter and drinking water for livestock.

According to Dr. Robert Sheridan of Shriners Children’s Boston, children are especially susceptible to frostbite because their bodies lose heat about four times faster than adults.

“The body responds to freezing temperatures by sending blood away from the hands and feet to protect the core, but this also reduces sensation in those extremities,” Sheridan said in a news release Thursday. “Children and teens may not realize how cold their fingers and toes have become and could stay outside longer than is safe.”

Early signs of frostbite include redness, stinging, tingling sensations and numbness, according to the hospital, and skin may harden, blister or darken in severe cases, indicating tissue damage.

“If children are playing in extreme cold, they should come indoors every 15 minutes or so to warm up and check for signs of frostbite,” Sheridan said.

People can visit MEMA’s website to find a list of warming centers operated by local towns or cities and local organizations. Warming center info is also available by dialing 211 (or 866-811-5695) or texting your zip code to 898-211 for a list of locations.