How is lake-effect snow formed?

Lake-effect snow is formed by cold air flowing over warm lake water.

The warm lake water transfers its heat into the air's bottom layer. This is done by evaporating lake moisture into the cold air right above the surface of the lake.

Warm air is lighter and less dense than cold air -- therefore the heated air then rises and begins to cool off in the colder air above.

As the air cools, the moisture from the lake that was evaporated into the air condenses and forms clouds.

If the air is humid enough where the clouds are forming then snow can be created and will begin to fall from the cloud.

Interactive Radars

Regional Headlines

This Week's Circulars

Regional Radar Image

Live Traffic Cameras

Cameras provided by PennDOT

Historical Averages

High Low
Current 65°F 54°F
Average 75°F 53°F
Record 94°F May 30, 1987 36°F May 30, 1949