If you have a warrant out for your arrest in any court there is always a chance that you could get arrested on that warrant at any time if you have contact with any sort of law enforcement. Whether you will actually get arrested under the circumstances you set out in your question would depend upon numerous factors and is not something anyone could answer at this point.
You may be able to avoid this concern by getting the warrant quashed before you travel. Of course, this would mean you would need to go back to the court and face the underlying issue and that could get a bit complicated depending upon the reason for the warrant and the criminal charge associated with it.
You should speak with a criminal defense lawyer who can analyze your situation more specifically.
It may depend on where the warrant is and whether it is for a felony or a misdemeanor. Felony warrants tend to cause more problems because they will be enforced in a larger geographic area. IF you have a misdemeanor from any King County court and fly out of Seatac you could be nabbed, if it's from another county you might not be in much danger. Once you leave the country and go through customs you could be denied entry into the other country and then be arrested upon your return. You should probably talk to a lawyer.