Weather forecasters said late Thursday night that heavy snow and strong winds would create blizzard conditions overnight in southern Maine and that the region would have as much as a foot of new snow by Friday morning.

Portland had received just over 6 inches of light, fluffy snow by 9 p.m. Thursday, while Old Orchard Beach and Standish each had 7 inches.

A blizzard is defined by meteorologists as a snowstorm with sustained winds of at least 35 mph and visibility of less than a quarter-mile for three hours or more.

“It’s pretty darn close now,” James Brown, a meteorologist for the National Weather Service in Gray, said just after 9 p.m. Thursday. “It will become a blizzard overnight.”

The storm, which began Thursday morning, also brought some of the coldest weather that Maine has seen in years.

The temperature in Portland was 5 degrees below zero at 9 p.m. – the low for the day to that point – with a wind chill of minus 26.

Brown said the high temperature for the day was just 12 degrees, at 12:01 a.m. That set a record for the coldest high temperature on Jan. 2. The previous record, 13 degrees, was set in 1968.

And after that cold start Thursday, the temperature only fell, without setting any other records.

The lowest temperature in Portland for the date is 17 degrees below zero, in 1968. The lowest temperature recorded in Portland for any date is 39 below, on Feb. 16, 1943.

In far northern Maine, Caribou set a record for the date – 28 degrees below zero at 6:54 a.m. Thursday. That broke the previous record of 20 degrees below zero, set in 1968.

Brown said the weather service issued a wind chill advisory Thursday, effective through 1 p.m. Friday. He said it’s “dangerous” for anyone without proper clothing to be outdoors in such conditions.

Forecasters say the mercury could dip to 30 to 35 below Friday night in the mountains and in parts of northern Maine.

Thursday’s bitter cold, high winds and snow prompted state offices to close early, forced dozens of schools to cancel their first day back from vacation and grounded some flights out of the Portland International Jetport.

The storm followed a prolonged ice storm that crippled parts of coastal and central Maine last week, leaving more than 120,000 customers without power, many for several days. Thursday’s high winds caused much of the snow to blow and drift, decreasing visibility and creating the potential for more power outages.

Gail Rice, a spokeswoman for Central Maine Power Co., said crews were more concerned Thursday about the high winds than the snow, which was expected to remain light and fluffy. CMP reported 124 power outages just before 10 p.m. Thursday, almost all of them in Knox County.

Bangor Hydro Electric Co., which spent about a week restoring power in central and eastern Maine after last week’s ice storm, reported just four outages at 10 p.m.

Some relief is expected on Saturday, with temperatures in the teens. Portland could get temperatures in the 20s on Saturday, the 30s on Sunday and the 40s on Monday, before dropping again to single-digit lows on Tuesday and Wednesday.

Thursday’s storm coincided with high tides late Thursday morning, with near-shore waves in the 12-foot range. In Portland’s Bayside neighborhood, standing water was seen in several areas, including in front of the Whole Foods supermarket on Somerset Street.

Public schools in Portland, Gorham and Cape Elizabeth were among many in southern Maine that were closed Thursday, and more closures are likely for Friday. Portland had canceled Friday’s classes by Thursday night, and the city imposed a citywide on-street parking ban until 6 a.m. Friday.

For a list of the latest weather-related closings and cancellations, click here.

Gov. Paul LePage closed all state offices in Androscoggin, Cumberland, Kennebec, Knox, Lincoln, Oxford, Sagadahoc, Waldo and York counties as of 2:30 p.m. Thursday.

Speed limits on the Maine Turnpike and Interstate 295 were reduced to 45 mph, although that did little to prevent accidents, which were reported throughout the day. None was serious.

Maine State Police said a crash on I-295 northbound near Exit 11 slowed traffic during the morning commute. Crashes also were reported in Pownal, Bowdoin, Kennebunk and South Berwick.

Late Thursday night, Buxton police were investigating a head-on collision between two pickup trucks on Route 202 near Pease Road. Two people were taken to hospitals with non-life-threatening injuries. Police said the crash was caused by slippery roads.

The Portland jetport had nearly two dozen flight cancellations Thursday, said director Paul Bradbury, and those cancellations could affect travel well into Friday.

“The airport will be open, but it doesn’t mean there will be a lot of aircraft coming in and out,” he said.

Nationwide, more than 1,800 flights were grounded Thursday in advance of the storm.

The Boston area was expected to get a foot of snow by early Friday morning. Many flights were canceled Thursday at Logan International Airport, which was scheduled to close Thursday night.

Dennis Hoey can be contacted at 791-6365 or at:

dhoey@pressherald.com

Eric Russell can be contacted at 791-6344 or at:

erussell@pressherald.com

Twitter: @PPHEricRussell