I had the same experience driving from Reading PA to Lancaster PA on Sunday morning. Went from cloudy skies with temperatures near 40 to heavy snow with the temperature dropping to 34 in just a few miles. The ground had about a half inch however there was slush covering the highway. There is no significant elevation in that area however there was heavy snow with visibility down to 1/4 mile. Scary thing is the other drivers were not slowing down as much as they needed to.