The Boston area's second rush-hour snowstorm this season was expected to sock commuters this morning with up to a foot of snow - leading officials to give schoolchildren in many municipalities a day off.
"A horror show," said Bill Simpson, meteorologist with the National Weather Service in Taunton.
"We wish the storm would start a little earlier and the roads would open in time for the commute, but unfortunately it ain't gonna happen," Simpson said.
Mayor Thomas M. Menino declared a state of emergency yesterday, effective at midnight, as did leaders of several other area cities.
Boston public school officials canceled classes today based on the prediction that the snow would fall quickly during the morning commute, according to spokesman Jonathan Palumbo.
"We wanted to make the decision [last night] so families would have the ability to make alternate plans for [this] morning," he said.
The Boston Centers for Youth and Families was working with the school system so that 16 of its centers will be open starting at 7:30 a.m. to help families struggling with child-care, Palumbo said.
After-school activities, evening events, and athletics were canceled as well, he said.
By 11 p.m., more than 260 school and college closings were reported, including Bridgewater-Raynham Regional, Brookline, Framingham, and Roxbury Community College. About two dozen cities and towns declared snow emergencies, and Somerville, Quincy, and Woburn enacted snow emergency restrictions last night.
Also, emergency parking rules on the state's Department of Conservation and Recreation roads took effect at midnight, after officials announced DOC ice rinks would be closed today. The US District Court in Boston canceled jury duty today.
National Weather Service meteorologists said they expected snow to start after midnight and to begin falling harder during rush hour. The storm should last until this afternoon or evening, leaving 8 to 12 inches of snow in the Boston area. Some areas - Cape Ann, Worcester, and the Merrimack Valley - could get as much as 14 inches. The South Shore may get 4 to 8 inches of snow, with Cape Cod possibly receiving 1 to 3 inches.
The storm comes after a winter reprieve when an unusual burst of sunshine made temperatures reach into the 60s, following one of the snowiest Decembers on record.
Now, it is back to dig, shovel, and bundle.
Temperatures are expected to settle back to normal for January, in the 30s and lower for much of the week, with the possibility of single digits Wednesday night in the suburbs.
Menino said today's storm could be all too similar to one almost exactly a month ago that left afternoon commuters stuck in traffic for hours, cursing into their cellphones, with snowplow drivers unable to alleviate the gridlock. Menino, who drew criticism for the snarls, pointed fingers at state officials after that storm, saying they were not prepared, while Governor Deval Patrick chalked up the problems to bad timing. The Dec. 13 storm dropped about 10 inches on Boston, similar to this storm's projected accumulation.
"That's the worst time, during rush hour, to have snow come in," said Menino, who said he spent more than an hour yesterday coordinating with state government officials to try to avoid a repeat of last month's debacle.
Menino urged commuters to take public transit into the city or work from home if possible.
The Massachusetts Turnpike Authority used its roadside digital message boards yesterday to urge workers to take buses, trains, and subways, or leave earlier than usual for work so that car traffic would be staggered.
Travelers in and out of Logan International Airport were asked to check on their flights as some had already been cancelled last night.
State and city roadway crews planned to spend much of the night mobile on the roads - treating them with liquid calcium chloride so the snow will not stick, and plowing as the first flakes came down. The Massachusetts Emergency Management Agency was scheduled to open its operations center in Framingham, as a headquarters for safety, road, and utility officials. Patrick did not declare a state of emergency for the Commonwealth.
"If it's wet, heavy snow, and strong winds, certainly power's going to be an issue," said Peter Judge, spokesman for the emergency management agency.
"Obviously, the amount of snow may impact communities' ability to keep roads open for safety vehicles," he said.
Boston's emergency declaration means city residents were prohibited from parking on major arterial roads, where snow emergency signs are posted, or within 20 feet of an intersection.
On secondary streets, parking is allowed only on the odd side. The city has agreements with local garages to provide discounted parking for residents during the storm.
Noah Bierman can be reached at nbierman@globe.com.
