We had a year like this before, 1995. We were under snow cover for 3 months. We got 36 inches on March 31st that year. Generally, we have no snow cover for longer than 2 weeks, although last year and this, we had two periods of 3 weeks.
They were completely wrong on the news about this last one., They kept saying that Maryland, South Jersey & Delaware were going to be the northern range of the really deep stuff. The forecast for Philly was 6 to 12" and less for west of the city. Our airport got the highest cover of any at 29" I'm 15 miles west and got 24".