Check this: "Declining Jurisdiction
Under the UCCJEA, a court with initial
jurisdiction; exclusive, continuing jurisdiction;
or modification jurisdiction may
decline to exercise jurisdiction on two
grounds: inconvenient forum and unjustifiable
conduct.
Inconvenient forum. Under section 207 of
the UCCJEA, a court may, after taking into
account specified factors, determine that
another State is better able to decide custody.
These factors include whether domestic
violence has occurred and, if so,
which State can best protect the parties
and child; how long the child has lived out
of State; where the evidence is located;
and which court is most familiar with the
case." (at p. 7)
http://www.ncjrs.gov/pdffiles1/ojjdp/189181.pdf
You have mentioned going back for modifications; I'm not certain what that means.