Hurricane Patricia (IMAGE) University of California - Santa Cruz Caption Hurricane Patricia was the most intense tropical cyclone ever recorded in the Western Hemisphere as it approached the west coast of Mexico in 2015. Researchers detected a reverse positron beam from a terrestrial gamma-ray flash associated with lightning in the eyewall of the hurricane. Credit NASA image by Jeff Schmaltz, LANCE/EOSDIS Rapid Response Usage Restrictions None 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.