Hi, 

It may be nimblewill, but since it is dormant, we cannot be sure. The strawlike appearance now does appear to be nimblewill, but it can be confused with other warm-season perennial lawn weeds like Bermuda grass. 

Nimblewill is technically a native plant, but we understand it is undesirable in a lawn setting. The link provided will list control options and active ingredients for herbicides that can be used for it. Overseeding with a desired grass type, in this case a tall fescue blend, will help thicken the turf growth to outcompete undesirable weeds. Lawn overseeding for tall fescue is best in the fall, but if you want to spot overseed this spring after you remove the weeds, that can help prevent others from growing in over the summer. Look for a certified weed-free grass seed mix and one recommended for the Chesapeake Bay/Mid-Atlantic area. 

Let us know if you have other questions. Or if you want to send in other photos when the weed greens up (you won't be able to spray it until it is showing active growth anyway). Or you can wait until fall and strip the existing turf cover and perform a total lawn renovation. 

Emily