I'm really having a difficult time seeing how a plaid could be more versatile in the winter climate of the District of Columbia than some form of jacket or coat. There is a good reason why plaids are rarely worn in Scotland today: there are so many better alternatives!

Don't get me wrong, though. A day plaid is a very nice thing to have and does come in handy from time to time, but as Jock Scott and some others have pointed out in the past, they really can be a bother! They slip and slide, they get wet, they leave parts uncovered.

If you don't mind looking like you are wearing a costume, then no problem. If you want to stay dry/warm, get a coat. You can easily remove it when you get warm.

PS: I live in Kentucky. Our weather isn't much different than DC. I've got all sorts of Barbours, and tweed overcoats, fleece jackets, down parkas, mackintoshes, shooting coats, gortex rain coats, gortex foul weather coats--all sorts of things! The back of my jeep usually has 3 or 4 jackets of various types to choose from when needed. I also have a MacLean hunting tartan blanket in there as well. It gets used at sporting events!