Regrettably, it does have to be actively absorbing herbicide. Right now, it may require two shots, which I really don't like doing as it's more toxic than it has to be and can take a toll on surrounding grasses, which don't appear in the above photograph. Fescues, in particular, can be a bit sensitive. Bluegrasses tend to be relatively bulletproof. :-) That's fine, so if you want to treat it now, go right ahead. And definitely don't wait until May. But it's best to wait for full reactivation and daytime temps in the fifties. If you follow the advice on the bottle, they do recommend active growth to avoid overuse of the product and too much toxicity in the soil. I'm not sure of your locale; for me, in eastern PA, perennial weeds don't get sprayed until early April (this year, probably a bit later; spring is late regardless of the calendar). Further south, that will be earlier.

Looks like Geum canadense, White

Those are terrible photos - almost impossible to distinguish what the weeds look like in that indistinct pulled clump. Next time take a careful shot of them growing in place. As best as I can tell, that looks like ground ivy, Glechoma hederacea. That is an evergreen creeping vine that will invade lawns and flower beds. And any pre-emergent will have no effect on it. Even a very lush, heathy lawn will have difficulty out competing ground ivy. Typically it will require the use of post emergence lawn herbicides containing dicamba, 2, 4-d and triclopyr (like Trimec). Fertilizing the law will only serve to fertilize the ground ivy as well.

It looks like clumps of warm season grass growing in a cool season lawn