Aside from B'way bombs, does anybody else who grew up in NY remember the bomb drills we had in the 50's? Obviously, if you were gonna be nuked, you were gonna be nuked, and terrifying kids in advance with horrifying scenarios (I lived uptown, and actually remember wondering if I could run all the way home before the firestorm hit!) did not help one bit then, and is not going to help today.
Advance notification would only give the pols time to get hysterical - and I doubt that one life would be saved because of it.
Prevention is the only way - get them before they get us.