Pennsylvania Braces for Significant Snow and Lake-Effect Impacts as Rain Turns to Snow Overnight Into Friday Morning

Pennsylvania — A major winter weather event is unfolding across the state tonight, as rain changes over to periods of accumulating snow, with the heaviest impacts expected across northwestern Pennsylvania. Forecast guidance shows dangerous travel conditions developing late tonight through Thursday morning, driven by falling temperatures, accumulating snow, and lake-effect bands. Meteorologists warn that this storm will bring rapidly deteriorating road conditions, particularly across the northern and western half of Pennsylvania, as temperatures plunge into the teens and 20s.

Heaviest Snow Focused on Northwestern Pennsylvania

According to the final snowfall forecast, the greatest snow totals are expected across northwestern Pennsylvania, where lake-effect snow will significantly enhance accumulations.

Forecast snowfall totals include:

• 6 to 10 inches across inland portions of Erie, Crawford, and Warren Counties
• 4 to 6 inches across parts of north-central Pennsylvania
• 2 to 4 inches across much of western and central Pennsylvania
• 1 to 2 inches or less farther south and east

In the hardest-hit lake-effect zones, localized totals could exceed 10 inches, especially where snow bands persist.

Lake-Effect Snow Continues Through Thursday

As colder air pours in behind the system, lake-effect snow showers are expected to continue through Thursday morning and afternoon, prolonging hazardous conditions in areas already impacted by earlier snowfall. These lake-effect bands can be highly localized, meaning snowfall totals may vary sharply over short distances, especially near Lake Erie and inland snowbelt communities.

Dangerous Travel Conditions Expected

The combination of accumulating snow and rapidly falling temperatures will create icy and snow-covered roads, particularly late tonight and during the Thursday morning commute. Officials caution that travel could become extremely difficult, especially in areas receiving 2 to 4 inches or more. Sudden drops in visibility and slick road surfaces are likely, increasing the risk of accidents.

School Delays and Closures Likely

Forecasters expect numerous school delays or closures, particularly in districts located within the 2 to 4 inch zone or higher. The timing of the heaviest snow — overnight into early morning — increases the likelihood of transportation disruptions.

Snow Squalls Possible Thursday Afternoon

Even as steady snowfall tapers in some areas, snow showers and snow squalls may develop Thursday afternoon, especially across western and northern Pennsylvania. These squalls can produce brief whiteout conditions, catching drivers off guard with little warning. Residents are urged to stay alert for rapidly changing conditions throughout the day.

Lighter Impacts Farther South and East

The farther south and east across Pennsylvania, the less snow is expected, with some areas seeing flurries or brief snow showers but minimal accumulation. Southeastern Pennsylvania, including the Philadelphia region, is expected to see little to no measurable snow.

Why This Matters Nationally

This storm highlights the power of lake-effect snow systems, which can produce extreme localized impacts even when surrounding areas see far less snow. It also serves as a reminder that mid-winter Arctic air masses can quickly transform rain into dangerous snow and ice events.

NapervilleLocal.com will continue monitoring major national weather events and providing accurate, location-verified reporting when storms pose significant risks across the country.