Particularly dangerous situation

In weather forecasting in the United States, "particularly dangerous situation" (PDS) is the wording used by the National Weather Service to convey special urgency in watch or warning messages for unusually extreme and life-threatening severe weather. It is used in the format "This is a particularly dangerous situation..." at the discretion of the issuing forecaster. A watch or warning bearing the phrase is referred to as a PDS watch or PDS warning.