Judge Warning graduated from the University of Washington in 1976 and from the University Of Washington School Of Law in 1979.

He was in private practice in Cowlitz County for 16 years, with an emphasis in criminal defense and business litigation. In 1996 he was elected to the Cowlitz County Superior Court Bench.

Judge Warning has served as Dean of the Washington Judicial College in 2006, where he has also taught. He has been both Secretary and Trustee on the board of the Superior Court Judges Association.

Judge Warning started the Cowlitz County Drug Court in 1999, and presided over that program for five years.