This article describes severe weather terminology used by the National Weather Service (NWS) in the United States. The NWS, a government agency operating as an arm of the National Oceanic and Atmospheric Administration (NOAA) branch of the United States Department of Commerce (DoC), defines precise meanings for nearly all of its weather terms. This article describes NWS terminology and related weather scales used by the agency. Some terms may be specific to certain cities or regions. Specific Area Message Encoding (SAME) product codes assigned to each term for NOAA Weather Radio (NWR) broadcasts are included in parentheses following the title of the described alert type if used; products that do not have a specified code are identified where applicable as Non-Precipitation Warnings/Watches/Advisories (NPW), Coastal Flood Warnings/Watches/Advisories (CFW), Marine Weather Statement (MWS), Surf Discussion (SRD) or Winter Weather Warnings/Watches/Advisories (WSW) as defined by NOAA. Definitions of severe weather alerts The NWS divides severe weather alerts into several types of hazardous/hydrologic events: Severe local storms – Short-fused, small-scale hazardous weather or hydrologic events produced by thunderstorms (including large hail, damaging winds, tornadoes, and flash floods). Winter storms – Weather hazards associated with freezing or frozen precipitation (freezing rain, sleet, and/or snow), or combined effects of winter precipitation and strong winds. Fire weather – Weather conditions that contribute to an increased risk and help cause the spread of wildfires. Flooding – Hazardous hydrological events resulting in temporary inundation of land areas not normally covered by water, often caused by excessive rainfall. Coastal/lakeshore hazards – Hydrological hazards that may affect property, marine or leisure activities in areas near ocean and lake waters including high surf and coastal or lakeshore flooding, as well as rip currents. Marine hazards – Hazardous events that may affect marine travel, fishing and shipping interests along large bodies of water, including hazardous seas and freezing spray. Tropical cyclone hazards – Hazardous tropical cyclone events that may affect property in inland areas or marine activities in coastal waters, resulting in wind damage, storm surge, tornadoes and flooding rain. Non-precipitation hazards – Weather hazards not directly associated with any of the above including extreme heat or cold, dense fog, high winds, and river or lakeshore flooding. Severe local storms Tornado watch (TOA; yellow box in some select NWS documentation, red box in most other media) – Conditions are favorable for the development of severe thunderstorms and tornadoes in and close to the