Torpedograss?

Need a closer photo to determine, but common rhizomatous weed grasses in the Seattle area include quackgrass, velvet grass and bentgrass. Bent grass is a very low growing weedy grass (in lawns - but used frequently with golf course greens) so this is not a strong suspect. I'd lean heavily towards the quackgrass. These do not respond to most lawn weed control products and are difficult to remove manually. They are controlled by broad spectrum herbicides (i.e., glyphosate/RoundUp) however.

Thank you for mentioning Velvet grass because as soon as I saw a picture of the sead head, I knew I've seen that as well recently. I do not think it is my primary problem, but now I know to look out for it. Never heard of it. I'm not native to the PNW, but I used to think having a lawn here would be easy given the weather...I forgot almost everything grows here...haha.

I can see why one would say torpedograss because I saw that one too....they look pretty similar. The picture above was of a plant I deliberately took that looked spindly to show some of the characteristics. They usually start a little more bunchy, haven't seen a rhizome of that size (rather large looking in diameter from the pix of torpedo), and is doing best in the driest section of my lawn because it is always full sun and I think torpedo prefers water. The map of torpedograss does not include WA, but given how the climate has changed here in just the last decade, we may see more warm season grasses start to creep in.

I think quack is the correct answer...for some reason, good pictures of it are hard to come by. I will try to take some more right now.

I couldn't get a closer pic...my phone wouldn't focus, but this is the seedhead. Looks like quack.