Pennsylvania transportation officials are urging drivers to avoid unnecessary travel as a winter storm is expected to bring heavy, wet snow overnight Monday into Tuesday, potentially affecting morning and afternoon commutes.

The storm will bring up to 6 inches of snow accumulation in some areas, with snowfall rates of one-half to three-quarters inch per hour expected, and up to 1 inch per hour in some locations, according to the Pennsylvania Department of Transportation and Pennsylvania Turnpike Commission. In southeast Pennsylvania, snow will transition to sleet and freezing rain before changing to rain.

In the Lehigh Valley and Warren County, a Winter Weather Advisory updated Monday afternoon from the National Weather Service says to expect mixed precipitation from 4 a.m. to 1 p.m. Tuesday. Total snow accumulations up to 2 inches and ice accumulations around a light glaze are possible.

In a forecast update Monday afternoon, the weather service predicts a 60-90% chance of plowable snow (2 inches or more) along and north of I-78 and into the Pocono Mountains.

“Our latest forecast includes snowfall amounts less than 1″ for the immediate I-95 corridor, 1-3″ for areas just northwest of there, and in the 3-5″ range for the I-78 corridor” and northwestern New Jersey, the weather service wrote in a forecast discussion. Higher elevations (especially 1,500 feet and higher) in northwestern New Jersey and across the Poconos could see total snowfall in the range of 4 to 8 inches.

Beginning at 5 a.m. Tuesday, Dec. 2, Pennsylvania transportation officials say vehicle restrictions will take effect on multiple highways across the state. Tier 1 restrictions will apply to Interstate 78, I-80 from Exit 173 at Lamar to the New Jersey border, I-81 from I-78 to the New York border, I-84, I-180, U.S. 22 from I-78 to the New Jersey border, Route 33, and the Pennsylvania Turnpike Northeast Extension (I-476) between the Lehigh Valley and Clarks Summit interchanges.

Tier 3 restrictions will be in place on I-380.

Under Tier 1 restrictions, tractors without trailers, tractors towing unloaded or lightly loaded trailers, unloaded cargo delivery trucks, passenger vehicles towing trailers, recreational vehicles, school buses, commercial buses, motor coaches, and motorcycles are prohibited. Tier 3 restrictions ban all commercial vehicles except loaded single trailers with chains or approved alternate traction devices, along with school buses, commercial buses, motor coaches, motorcycles, RVs, and passenger vehicles towing trailers.

Speed limits will be restricted to 45 mph on affected roadways for all vehicles while restrictions are in place. Commercial vehicles not affected by the restrictions must move to the right lane.

PennDOT and PA Turnpike crews will pre-treat roadways ahead of the storm to prevent ice from bonding with pavement. However, drivers may still encounter icy spots, particularly on bridges and highway ramps where ice can form. Roads that appear wet may actually be icy due to freezing temperatures.

Last winter in Pennsylvania, preliminary data shows 8,329 crashes occurred on snowy, slushy, or ice-covered roadways, resulting in 29 fatalities and 2,959 injuries. Eleven people who died weren’t wearing seat belts, and 17 fatalities involved crashes where a driver was going too fast for conditions and drove out of their lane.

Pennsylvania law requires drivers to remove accumulated ice or snow from their vehicle, including the hood, trunk, and roof, within 24 hours after a storm ends. This applies to all vehicles, including commercial vehicles. Drivers violating the law face a $50 fine. Additionally, drivers can be cited up to $1,500 if snow or ice dislodges and strikes another vehicle or pedestrian, causing death or serious injury.

PennDOT advises motorists who must travel to slow down gradually, turn on headlights, stay in their lane, increase following distance, and avoid distracted driving. During whiteouts, drivers should only come to a complete stop when they can safely pull off the roadway and should not stop in the flow of traffic.

When encountering plow trucks, drivers should stay at least six car lengths behind operating equipment and never try to pass or get between trucks plowing side by side. Pennsylvania state law requires vehicle lights to be on every time wipers are in use due to inclement weather.

Motorists can check conditions on more than 40,000 roadway miles by visiting 511PA.com or using the free 511PA smartphone app, which provides traffic delay warnings, weather forecasts, and access to more than 1,200 traffic cameras.

Restrictions will be communicated via variable message boards, the 511PA traveler information website, and smartphone apps. Motorists can sign up for personalized alerts on the website. Restrictions will be lifted when conditions are safe.

Generative AI was used to organize information for this story, based on data provided by PennDOT and the Pennsylvania Turnpike. It was reviewed and edited by lehighvalleylive.com.