Cold Alerts: What Do They Mean?

With winter rapidly approaching, it's important to know the different cold alerts issued by the National Weather Service and what they mean.

Wind chill occurs when winds cause cold temperatures to feel even colder and can lead to a dangerously cold environment.

A Wind Chill Warning is issued when extreme values of cold wind chill is expected or occurring. A Wind Chill Watch is issued when extreme values of cold wind chill is possible. A Wind Chill Advisory is issued when cold wind chill values are expected or occurring, but are not extreme or dangerous.

Temperatures below 32 degrees Fahrenheit pose a dangerous risk to human health and precautions must be taken. When this happens, the National Weather Service will issue the appropriate advisories, watches, and warnings.

A Hard Freeze Warning is issued when temperatures are expected to drop below 28 degrees Fahrenheit for a long period of time. A Freeze Warning is issued when temperatures are expected to drop below 32 degrees Fahrenheit for a long period of time. A Freeze Watch is issued when there is potential for temperatures to drop below 32 degrees Fahrenheit in a widespread region. A Frost Advisory is issued when areas of frost pose a threat to sensitive vegetation.

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Image: Ice glaze on grass, taken in Pennsylvania, USA during freezing rain on December 16, 2007. (Murali Narayanan).
Source: weather.gov