Lol, once you get a little further north (I'm only about 2 hours north of DC) you'll find a foot of snow is far from enough to shut everything down (though it will still close most schools,
Around here they'll close school if its partly cloudy,
so the kids borrow Mom's car and go skiing!
When I was a kid we'd wait by the radio hoping for a cancellation and we wouldn't get it. More than once our bus got stuck on the way to school (and I don't mean we slid off the road, we just couldn't get through). Today there is no way they'd let the busses out in those conditions.
the roads and businesses are generally open). After the blizzard last year that dumped over 3-ft of snow I was out the next day when many of the roads were only partially cleared and still had 6+" of snow on them and deeper drifts. I drove my Patriot (4X4) with the OE tires (Firestone Affinity) and never got stuck myself, though I did get blocked by several other drivers I had to help dig/push out (all FWD cars, except one idiot in an AWD Audi RS4 with summer tires).
Dedicated snow tires make a big difference. The silliest thing I see is people who think more power is the solution and go fishtailing all over the place and endangering the rest of us.
I've had my XJ with Aggressive AT tires up unplowed (and unpaved) mountain roads with well over a foot of snow and steep grades, I could even see the imprints from my axles in the snow.
As for the OP's original question you probably don't "need" snow tires in MD (at least in the Baltimore area, the mountainous areas in western MD may be a different story) with the exception of the once in 15-20 year blizzards, but they definitely are nice to have (note: "winter tires" aren't just for snow, the softer compound improves traction in cold weather as well). While the OE AS tires on my Patriot may have "gotten the job done" (though I don't know if I would have been ok if I only had FWD),
I am a FWD fan, but FWD does have its limits. Good tires make a huge difference, but its not as good as 4wd. The big problem comes when climbing a hill with a sharp curve in deep snow. With FWD the back tires are dragging through the snow the fronts have just pushed into their path, and the rears can't help as they would with AWD or 4wd.
it definitely would have been nice to have "real" snow tires or even A/Ts.
When it comes to going straight ahead, we can get away with all-season tires on our Wrangler, but when it comes to stopping and cornering its a monster. Snow tires are a must.
All things considered, so much depends on the type of snow one is driving in. A foot of light powder is easy, even climbing a hill; if its mushy, half that can be a problem, even with AWD. I'm thinking it was about 8" of mush that stopped my Bravada (with all-season tires) in my driveway. On another occasion in the same driveway the same Bravada got through 17". As for the roads, in our area the highway trucks are out there every few inches, except at night, but when I leave for work in the morning (3:30) I'm just about the only car on the road so I can build momentum on the downgrades and scamper up the hills easy enough.