... that would be Santa. But wait! Read this closely:
Not only does NORAD operate the finest tracking system in the world but recent upgrades apparently have given the system a capability of seeing about three hours into the future, if my back-o-the-hand calculations are accurate. This enhanced performance capability should prove useful in other (i.e., military) applications, no doubt.
OK... that said... we'll be tracking Santa off and on throughout the day!
Update, 0400 hrs: As predicted... Airborne!