Wavy Jet Stream (IMAGE) Northern Illinois University Caption New research finds a strong relationship between a wavy jet-stream pattern over the Pacific Ocean and severe US hailstorms. Credit Victor Gensini, Northern Illinois University Usage Restrictions Please credit. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.