Reasons for a Civil Emergency Message include nuclear accidents, toxic chemical spills or a National Terrorism Advisory System alert. The National Weather Service issues a Civil Emergency Message when a non-weather related emergency of a time-critical nature needs to be reported to the general public immediately.
Civil Emergency Messages warn the general public of imminent threats to public safety or threats that are in-progress as of the message broadcast. A Civil Emergency Message has a higher priority than a Local Area Emergency, but is not as specific as a Civil Danger Warning.
Generally, a Civil Emergency Message contains the exact time and date of the message broadcast, the name of the authority requesting the broadcast and several sentences of content describing the emergency at hand.
Another example of a situation that could result in the broadcast of a Civil Emergency Message is a citywide loss of water service due to a catastrophic reservoir failure. In this instance, the message might instruct residents to refrain from unnecessary water usage such as watering lawns or washing cars.
An additional example of a situation that may warrant a Civil Emergency Message broadcast is severe flooding, even if the cause of the flood is a weather-related event.