Green: Low hazard. “Zoom-Prevention.” This alert is set when a tropical cyclone has reached when a 63 mile per hour storm is 24-72 hours away.
Yellow: Moderate Hazard. “Zoom-Preparation.” Set when a tropical cyclone is 12 – 60 hours out, and has a minimum wind speed of 63 miles per hour.
Orange: High Risk. “Zoom-Alarm.” Set when the storm is 6 to 36 hours out an orange altert is issued.
Red: Danger maximum. “Approach-Effect.” This alert is issued when a hurricane is at maximum 18 hours out, and appears to be headed for a direct strike.