One thing for sure, what Chas has is not crabgrass. I line in NJ and
immediately recognized this as the same thing I have in a few spots in
my lawn. It's lighter in color, grows faster than the surrounding
grass, is most noticeable this time of year, then either greatly
diminishes or disappears by summer, only to reappear in the same spot
next spring. It doesn't look at all like crabgrass, which grows
lower to the ground. This stuff grows low for the first inch or so,
then shoots up straight.

It doesn't respond much to Acclaim, which is effective against some
undesirable grasses, especially crabgrass. So, I whacked the few
spots I had it growing in with Roundup and reseeded before it spreads
more and gets way out of control.

I may pull a remaining clump and take it to the local state agri
service for identification, as I've been curious as to exactly what
this is for awhile. Quack grass is on my list of possibilities too.