Here is a press release that our Portland Metropolitan area Public Information Officers put together to explain this:
The U.S. Department of Homeland Security, Federal Emergency Management Agency (FEMA), the Federal Communications Commission (FCC) and the National Oceanic and Atmospheric Administration (NOAA) will conduct the first nationwide test of the Emergency Alert System (EAS) on Wednesday, November 9th 11:00 a.m. P.S.T.
When the test occurs, please DO NOT call 911.
The public will hear a three-and-a-half minute message clearly indicating, "This is a test." The message will be the same across radio, television, cable and satellite outlets.
To further avoid confusion, TV outlets may prepare an on-screen “crawl” or other visual reminder indicating this is merely a test. Click here for more information: http://www.fema.gov/emergency/ipaws/eas_info.shtm.
The national-level EAS is an alert and warning system that enables the President to address the American public during extreme emergencies. This test will resemble frequently conducted, local EAS tests. However, this is a national event. As such, this test will broadcast to television and radio outlets throughout the country.
This event serves as a reminder that everyone in the Portland area should sign up at http://www.publicalerts.org/ to receive emergency notifications via landline phone, cell phone, text and email.
In cases of an actual emergency, the PublicAlerts system enables local response personnel to notify homes and businesses as needed with information to protect life and safety.