Snow tops the fencing as flags fly at Fabbri Park in Gallitzin on Monday afternoon. Forecasters have issued a winter storm watch through 7 p.m. today, with 4 to 6 inches of snow expected to fall before changing to sleet, freezing rain and rain as the storm progresses. Mirror photo by Patrick Waksmunski

Area school districts announced plans Tuesday afternoon to use flexible instruction days today and PennDOT has posted vehicle restrictions as a winter storm moved into the area overnight.

The National Weather Service in State College issued a winter storm watch through 7 p.m. today, predicting that heavy snow will accumulate about an inch an hour for a total accumulation of 4 to 6 inches in the region. A light glaze of ice is also possible, the weather service stated.

The snow could make the morning commute difficult, said Accuweather senior meteorologist Tom Kines.

Precipitation will start off as snow, and throughout the day it will transition to sleet or freezing rain before changing to rain, Kines said.

“The amount of snow we get depends on how quickly the changeover happens,” he said.

Kines expects traveling to be slow this morning and into the early afternoon.

PennDOT and the Pennsylvania Turnpike Commission are advising motorists to avoid unnecessary travel during the storm.

Road crews were out Tuesday pretreating roadways where necessary to help prevent ice from forming a bond with the pavement during the early stages of the storm, PennDOT said in a news release.

“However, salt is not a silver bullet, and drivers may encounter icy spots on the roadway,” the news release stated. “With freezing temperatures, roads that look wet may actually be icy, and extra caution is needed when approaching bridges and highway ramps where ice can form without warning.”

A Tier 1 vehicle restriction — prohibiting tractors without trailers, passenger vehicles towing trailers, buses and more — will go into place at 6 a.m. today on I-80 from I-79 to I-180, on I-76 (turnpike) from New Stanton to Breezewood and on the entire length of I-99.

As the storm moves across the state, PennDOT will institute additional restrictions. Road conditions and restrictions can be found at 511PA.com.

Blair County Emergency Management Director Mark Taylor said he was watching the forecast and is expecting the area to get 3 to 5 inches of snow during the storm.

“This should arrive around 3 a.m. to 4 a.m. Wednesday morning, so the commute to work and getting students to school might be a struggle,” he said. Ridge tops could see wind gusts up to 40 mph, he added.

It’s typical winter weather most people in the region are used to at this time of year, Kines said.

While the storm isn’t expected to bring an unusual amount of snow, the EMA center is arranging warming shelters in case the need arrives.

For those who are traveling in the snow, Taylor said drive slowly and make sure to carry cellphone chargers and blankets in the vehicle.

Residents should have supplies of water and food in the event of an emergency, said Bedford County Director of Emergency Services Alex Delia. Bedford County, too, will open shelters if the need arises, he said.

As of late Tuesday afternoon, multiple school districts were posting flexible instruction day information on websites and Facebook posts, including Altoona, Hollidaysburg, Bellwood, Spring Cove, Williamsburg and Claysburg-Kimmel.

Mirror staff writer Cati Keith can be reached at 814-946-7535.