An extreme wind warning (SAME code EWW) is an alert issued by the National Weather Service for areas that will experience sustained surface winds 100 knots (115 mph, 185 km/h, 51 m/s) or greater within one hour, due to a landfalling hurricane. Extreme wind warnings are intended to provide guidance to the general public at a county or sub-county level when such winds pose a significant threat of casualties. Their issuance is intended to cover as precise of an area as possible and can be issued no earlier than two hours before the onset of extreme winds.