National Weather Service United States Department of Commerce

Hazardous Heat Expanding into the Central and Eastern U.S.; Severe Thunderstorms in the Midwest into the Upper Great Lakes

Hazardous heat will expand into the Central and Eastern U.S. this week. Extremely dangerous heat, particularly for urban areas of the Southeast and East Coast, is forecast Monday through midweek. Many daily record highs are possible. Strong to severe thunderstorms are expected over parts of the Midwest into the Upper Great Lakes Region Monday, with damaging winds as the primary threat. Read More >

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Click for a larger image. (Courtesy of National Oceanic and Atmospheric Administration/Department of Commerce)
 
Watches, Warnings, and Advisories

Watcheswarnings and advisories are non-routine products issued by the National Weather Service. They are issued to alert you of meteorological events that could pose a threat to life and property. They are divided into three main categories...severe weather, winter weather and non-precipitation weather (fog, dusts storms, etc).

watch is issued when the risk of hazardous weather or hydrological event has increased significantly, but its occurrence, location and/or timing is still uncertain. It is intended to provide enough lead time so those who need to set their plans in motion can do so.Watches evolve into warnings, advisories or they are canceled.

Warnings are issued when a hazardous weather or hydrologic event is occurring, is imminent or has a very high probability of occurrence. It is used for conditions posing a threat for life or property. The National Weather Service is the single "official" voice when issuing warnings for life-threatening situations.

An advisory is for less serious conditions that cause significant inconvenience and, if caution is not exercised, could lead to situations that may threaten life and/or property.