When the first hurricane emerges from the Atlantic Ocean or Gulf of Mexico this season, NOAA will use a new statistical model to help predict the start of the "eyewall replacement cycle," a key indicator that a storm’s strength and size is about to change dramatically. This new tool adds to a suite of forecast products NOAA uses to warn coastal communities of imminent threats. An eyewall is an organized band of clouds that immediately surround the center, or eye, of a hurricane. The most intense winds and rainfall occur near the eyewall.