National Weather Service United States Department of Commerce

Severe Thunderstorms and Heavy Rainfall in the Ohio Valley and Great Lakes; Winter Weather in the Northern Tier

A slow moving front extending from the Great Lakes region into the Plains will bring snow, wintry mix, and ice accumulation north of the front from the Upper Midwest into New England, and severe weather and heavy rain south of the front. Scattered severe thunderstorms with damaging gusts, severe hail, and heavy rain are expected across parts of the Great Lakes/Midwest through tonight. Read More >

Here's a snowfall map of reports we received at the NWS for the storm of the 8th of Dec, 2013. 

See this map on: https://www.erh.noaa.gov/ctp/pnsmaps/snow/archive/snowfall_12082013.php

The tight gradient along the Mason-Dixon Line was due to a very intense west-to-east band of snow which set up during the morning and early afternoon, producing 1-2" per hour rates.  Those rates are quite unusual.  As a note, the 7.5 inch report in West York is highly suspect, though, as a meteorologist from West York also sent a report of less than 5 inches.

snow map from public and spotter reports for 8Dec2013