5 per K with rain coming is, at 46% N per pound, 2.3 pounds of nitrogen per thousand.

Fortunately, with growth stopping a month ago, the roots probably aren't all that awake any longer.

Probably. Too bad I can't guarantee that. The chances of a burn aren't high, but they are there. If it were me, I'd hope for at least an inch to an inch and a half of rain to wash that out. If not, I'd be watering the lawn to assure it washes through at least some.

thanks morpheus. We had about an inch last night and were getting another inch+ tomorrow so hopefully enough washes through.

That should, with lowered temperatures, be sufficient! Urea takes about 3 days to flip to usable form once wet. It won't have time to completely flip over before being diluted out some.