Running from May 1 - May 6 2016 (go figure), Vibrant Response is an annual disaster response exercise ran by FEMA and USNORTHCOM. This years scenario is 10 kiloton terrorist nuclear detonation exercise and is to be held in Harrisburg, Pennsylvania.

[link to www.nv.doe.gov]

Also fills the false flag scenario gap quite nicely.
Vital Archer drills bringing nuclear weapons into the country, Marble Challenge drills finding the weapons and trying to disarm them, then Vibrant Response drills them exploding in a different location.

Anyways I just want this damn date range to pass without incident... but the continuously increasing amount of nuclear terrorism exercises taking place during time thisframe really isn't very comforting to say the least.