A storm predicted to blanket most of central Pennsylvania starting early Tuesday could dump as much as 6 inches of snow, the National Weather Service is warning.

The service has issued a winter weather advisory effective from 1 a.m. Tuesday to 1 a.m. Wednesday. It is forecasting a snowfall of 3 to 6 inches.

The advisory covers the counties of Dauphin, Cumberland, Perry, Lebanon, Mifflin, Northumberland, Columbia, Schuylkill, Lycoming, Snyder, Montour, Union, Sullivan, Juniata and Tioga.

“Plan on slippery road conditions, including during the morning commute on Tuesday,” the advisory states. “Be prepared for reduced visibilities at times.”