Hurricane_force_wind_warning
Hurricane force wind warning
Weather warning
A hurricane force wind warning is a warning issued by the National Weather Service of the United States when sustained winds or frequent gusts of 64 knots (118 km/h, 74 mph) or greater are either being observed or are predicted to occur.[1] The winds must not be directly associated with a tropical cyclone, or a hurricane warning will be issued.[2] If winds are lighter than 64 knots, a storm warning or gale warning will be issued.[3] The hurricane force wind warning is only used to warn of the possibility of wind which reaches hurricane-level severity, but lacks direct connection with a hurricane system.[3] The hurricane force wind can either signal sustained winds of 64 knots, or gusts of 64 knots lasting for two or more hours.[4]
In US maritime warning flag systems, two red square flags with a black square taking up the middle ninth of each flag is used to indicate a hurricane force wind warning (the use of one such flag denotes a storm warning or a tropical storm warning). The flags used to denote hurricane force winds are also used to warn of incoming hurricanes.[5]