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.

UNITED · FLIGHT UA 1709 LANDED 11:01 AM ET, ~17 MIN LATE · SCHEDULED TIME UNKNOWN

UA 1709 · BNA → IAD

took off 8:40 AM CT · landed 11:01 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?
8% chance · ±0 pts −5 pts · 24h
HOW SURE WE ARE Very high. The odds now come almost entirely from live conditions.
WEATHER FORECASTS LIVE IN THE AIR 0% 5% 10% 15% 20% 13h 6h Departs Lands