A winter weather advisory is in effect for the entire Channel 11 viewing area except the mountains where a winter storm warning has been issued through Saturday.
Snow fell at varying rates throughout the day Friday, said Severe Weather Team meteorologist Scott Harbaugh, and it will continue off and on into Saturday. Most locations can expect 2 to 5 inches of snow by Saturday morning.
There will be an additional inch or so of snow Friday night into Saturday morning. The mountains will pick up an additional 2 to 3 inches Friday night.
Drivers should use extra caution Friday and Saturday until all roads have been cleaned and cleared.
Pittsburgh Department of Public Works prepared for the storm by putting all DPW vehicles into salt and plow mode.
Director of Public Works Rob Kaczorowski said a full complement of crews will be working 12-hour shifts around the clock until all roads are cleaned.
By early Friday afternoon, accidents were reported in many areas and traffic was moving slowly throughout the entire region. Officials also issued a weather emergency on the Pennsylvania Turnpike. All travelers are urged to reduce speeds and keep alert for changing travel conditions.
Motorists should not attempt to pass turnpike trucks that are plowing or servicing the roadway.
PennDOT officials said Route 28 was closed in both directions in Armstrong County between Troy Hill Road in Rayburn Township and Ridge Road in Boggs Township due to a jackknifed tractor-trailer. The road reopened just before 5 p.m.
The HOV lane was closed on Friday so plows were able to concentrate on main roads, PennDOT officials said.
Allegheny County closed the Homestead Grays Bridge in both directions because of icy conditions.
Traffic moved slowly on all major roadways in and around Pittsburgh, though a couple of spots were worse than others, PennDOT officials said.
A crash on the Parkway West and slick road conditions around Green Tree Hill snarled outbound traffic, said spokesman Steve Cowan. The off ramp from Interstate 79 to the Parkway West inbound was heavily congested, though no accidents were reported.
One person suffered injuries when a driver lost control and slid off the pavement near the merger of Interstates 79 and 279 in Franklin Park during a snow storm Friday at 10:25 a.m.
In Peters Township, officials there declared a snow removal emergency. All on-street parking is prohibited so that snow removal operation may occur. The declaration of emergency will last for 24 hours beginning Friday at 2 p.m.
Pittsburgh Water and Sewer Authority crewsworked to fix three broken or leaking water lines, spokeswoman Melissa Rubin said.
A 10-inch main near Homer Street in Spring Garden burst Friday morning, forcing crews to close a section of Spring Garden Avenue while crews repair the line.
In Troy Hill, crews lowered pressure in a main at the intersection of Rialto and Ley Streets, where water started bubbling up through cracked pavement in the predawn hours. Rubin did not know when crews would be freed to fix the line. Homes in the area are experiencing low water pressure, but nobody has lost water service, she said.
In the West End, crews worked to fix a leaking water valve at South Main and Wabash streets, Rubin said.
The problems could be related to the cold weather, Rubin said, “but there‘s really no way to tell.”
In Westmoreland County, about 3 inches of snow had accumulated by late afternoon, but no serious accidents had been reported.
“We‘ve had a few minor accidents, nothing major. All roads are presently open,” said county Emergency Management spokesman Dan Stevens.
“Roads are in the process of being plowed and people should drive accordingly,” he said. “They do the primary roads first, then the secondary roads. People should take their time when they are out and allow themselves a little extra travel time with these conditions.”
State police Cpl. Donald Constantine of Troop T in New Stanton said there were no reported traffic problems along the toll road stretch near the interchange Friday afternoon.
He urged that “people take their time.”
“It looks like a lot of people are staying home and letting the plows do their work,” he said.
Several school districts announced early dismissals or program cancellations due to the snow.
Pittsburgh Public Schools canceled all evening classes and after school activities and Saturday detention.
West Mifflin Area School District will dismiss high school 20 minutes early, Superintendent Daniel Castagna said. Buses will be leaving the high school at 2 p.m. in order to keep buses for lower level schools moving on time.
The Moon Area School District canceled all elementary and middle school after-school activities. At the Moon Area High School, the Friday evening basketball game has also been canceled.
All evening activities in the North Hills School District are canceled.
The Penn Hills School District has canceled Friday night alternative education classes and Saturday detention at Linton Middle School and the high school, the district said, as well as the Sixth Grade Battle of the Classes and the freshman boys‘ basketball game. The Saturday SAT prep class also has been canceled but the SATs tests at the high school are still scheduled.
The Bentworth School District, Washington County, dismissed its middle and high schools at noon. Elementary school will be dismissed at 1:15 p.m.
The Bethel Park School District has canceled alternative education and talent show practice at the high school today. Bingo at Washington Elementary School has been canceled.
Plum High School students will be dismissed at 2 p.m., Plum Borough District said. Regular dismissal will be observed for middle and elementary schools.
The California Area School District dismissed its middle and high schools at 12:30 p.m. today. The elementary and intermediate/middle schools will be dismissed at 1:30 p.m.
The Montour School District has canceled all evening and Saturday morning activities. The Central Greene School District, Greene County, will dismiss all schools at 1 p.m. today.
The Carlynton School District issued an early dismissal notice Friday morning. Students at Carlynton Junior-Senior High School were dismissed at 12:30 p.m., and students at Carnegie and Crafton elementary schools will be dismissed at 1:30 p.m.
In addition, the district postponed all evening activities, including athletic practices and games and Friday‘s scheduled Crafton Elementary talent show.
All Community College of Allegheny County campuses and centers will be closing at 4 p.m. today. All evening classes and activities are canceled.
Point Park University announced classes and activities are canceled for Friday night and will resume tomorrow morning.
The Heinz History Center announced it has canceled its Night at the History Museum event this evening. The Pennsylvania Interscholastic Hockey League Outdoor Charity Series games scheduled Friday for the North Park ice rink have been cancelled, and have not been rescheduled yet. The rink will reopen Saturday. South Park ice rink is open Friday.
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Channel 11's news exchange partners at TribLIVE contributed to this report.