Tracked live by the FAA, but its flight plan was first seen after takeoff, so we don't know the scheduled time and can't say whether it's late.

REPUBLIC · FLIGHT YX 3420 LANDED 11:30 AM ET, ~9 MIN LATE · SCHEDULED TIME UNKNOWN

YX 3420 · DTW → IAD

took off 10:27 AM ET · landed 11:30 AM ET (scheduled time unknown)
Forecast issued Tue 10:00 PM ET · 12h after departure

Odds over time

Arrive at IAD more than 15 minutes late?
14% chance · ±0 pts +2 pts · 24h
HOW SURE WE ARE Very high. The odds now come almost entirely from live conditions.
LIVE IN THE AIR 0% 10% 20% 30% 40% 9h 6h Departs Lands