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 128 LANDED 5:41 PM PT, ~1 MIN LATE · SCHEDULED TIME UNKNOWN
Today

WN 128 · SLC → LAS

took off 5:47 PM MT · landed 5:41 PM PT (scheduled time unknown)
Forecast issued Tue 10:00 PM ET · 2h after departure

Odds over time

Arrive at LAS more than 15 minutes late?
64% chance · ±0 pts +18 pts · 24h
HOW SURE WE ARE Very high. The odds now come almost entirely from live conditions.
WEATHER FORECASTS LIVE IN THE AIR 0% 25% 50% 75% 100% 1.1d 12h 6h Departs Lands Now