what is a special marine warning

A Special Marine Warning is a warning issued by the U.S. National Weather Service for potentially hazardous marine weather conditions that usually last up to 2 hours. It is issued for short-duration severe local storms affecting coastal water areas. These conditions typically include sustained thunderstorm winds or gusts of 34 knots (39 mph) or greater, hail 3/4 inch or larger, or waterspouts. This warning is also used for other short-term hazardous weather events such as strong cold fronts, gravity waves, or squall lines that produce winds or gusts of 34 knots or greater. The warning is intended to alert mariners to dangerous conditions that require immediate attention and action to ensure safety on the water. Special Marine Warnings are distinct from other marine warnings like Small Craft Advisories, Gale Warnings, or Storm Warnings, and are specifically for quick-onset hazards such as sudden squalls or thunderstorms.