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.

SOUTHWEST · FLIGHT WN 4407 LANDED 8:16 PM CT, ~9 MIN LATE · SCHEDULED TIME UNKNOWN
Today

WN 4407 · FLL → STL

took off 6:52 PM ET · landed 8:16 PM CT (scheduled time unknown)
Forecast issued Tue 8:00 PM ET · 1h after departure

Odds over time

Arrive at STL more than 15 minutes late?
33% chance · ±1 pts −11 pts · 24h
HOW SURE WE ARE Very high. The odds now come almost entirely from live conditions.
WEATHER FORECASTS LIVE IN THE AIR 0% 20% 40% 60% 80% 1.2d 1d 12h 6h Departs Now Lands