Cold, arctic air is spreading across the eastern Great Lakes this afternoon. Lake effect snow showers have developed downwind of the lakes, impacting snow belts of northern Ohio, northwestern Pennsylvania, and western New York.
The lake effect snow showers will persist through the afternoon with light accumulations possible across the favored snow belts. Across the inland areas, just a few scattered snow showers or flurries are expected through this afternoon.
Tonight, a reinforcing arctic cold front will drop southward across the area. Winds behind this front will become well aligned allowing for a significant increase in lake effect snow showers and squalls downwind of the lakes. Heavy squalls with local white-out conditions are possible across the snow belt areas of northeastern Ohio, northwestern Pennsylvania, and western New York late tonight through Monday with significant accumulations expected. A few spots could even hear a rumble of thunder.
Outside of these favored areas, snow showers will be possible tonight and Monday, with lesser accumulations of snow the further you are from the lakes.
The lake effect snow showers and squalls will continue across the snow belt areas Monday night and Tuesday with additional significant accumulations possible.
Total snowfall accumulations across the snow belt areas through Tuesday could exceed a foot with locally over 18 inches possible where heavier squalls persist.
If you must travel across the snow belts tonight through Tuesday, be prepared for rapid changes in weather and road conditions.