The National Weather Service (NWS) is the official U.S. government agency charged with issuing weather watches, warnings, and advisories and is the source used by iAlert.com. Below is the criteria used by NWS forecasters when issuing a hurricane watch or hurricane warning for the affected coastline.
HURRICANE WATCH: means hurricane conditions of at least 74 mph (64 kt or 119 kph) are possible within 36 hours for affected coastline.
HURRICANE WARNING: means hurricane conditions of at least 74 mph (64 kt or 119 kph) are expected for defined coastal area within 24 hours or less.
A hurricane is more powerful than a tropical. Criteria for Tropical Storm