Reemerge
Strictly speaking, it means to emerge again.
Emerge:
verb (used without object), emerged, emerging.
1. to come forth into view or notice, as from concealment or obscurity:
reemerge. Dictionary.com. Dictionary.com Unabridged. Random House, Inc. http://www.dictionary.com/browse/reemerge (accessed: December 16, 2016).
However, there is a common and somewhat figurative usage that implies the passing of an event and the beginning of a return to normalcy or the familiar. This seems to be something of an off-label usage, and the examples I dug up from decent sources seem to show a self-conscious effort to explain what is perfectly obvious. So I can only suggest that this usage is informal.