Several accidents led to the closure of the northbound side of the F.E. Everett Turnpike in Merrimack.
As of 9 a.m., New Hampshire DOT says there are now alternating lane closures to get traffic through.
"We do have the speeds on the interstates downposted to 45 mph," said DOT spokesman Bill Boynton. "As usual, with winter maintenance, there's a lot of variables involved. Three of them are timing, temperature, and intensity and those all hit this morning."
Hometown forecaster Rob Carolan says the snow will move through the Manchester/Concord corridor and into Portsmouth through the morning, then taper off in the afternoon.
He says snow may continue throughout the day in the North Country.