A potent low pressure system (Nor’easter) is moving up the east coast producing very heavy rainfall right now. The low will intensify late tonight and draw in cold air changing over parts of it to snow! Yes, I said snow! Parts of extreme eastern Ohio, western Pennsylvania, northern West Virginia and extreme western Maryland will be under the gun for snow. Winter storm warnings (purple) and winter weather advisories (light blue) are already out for these areas. Significant accumulations are possible especially in the higher elevations like the Allegheny Plateau and Appalachians where over a foot of snow is likely. The snow should be winding down by early Tuesday morning.