Government agencies say all TV show broadcasts in the U.S. will be interrupted at 2 p.m. (Eastern Standard Time) on Wednesday for the first nationwide test of the country's Emergency Alert System (EAS). And they don't want consumers to panic, since "this is only a test."

The Federal Communications Commission, along with the Federal Emergency Management Agency and the National Weather Service, are concerned that the 30-second-alert broadcast may be misconstrued as an actual national emergency.

As noted by Ars Technica, previous local tests of the EAS that feature an on-screen message of an "emergency alert" sometimes failed to carry the disclaimer that there is no actual national emergency. And although the 30-second test will include an audio portion to advise consumers that "this is only a test," the FCC is warning the public not to panic should they see and hear the warning signals on every single radio and TV broadcast on Wednesday.

In public service announcements in both English and Spanish, the FCC says:

When you receive the test alert on November 9, don't worry. Remember, it's only a test.

According to the FCC, the 2 p.m. Wednesday test time was chosen because the "date is near the end of hurricane season and before the severe winter weather season begins in earnest. The 2 PM EST broadcast time will minimize disruption during rush hours, while ensuring that the test occurs during working hours across the United States."

This video shows a previous broadcast test of the Emergency Alert System by TV stations in Alaska.

About the Emergency Alert System (EAS) [FCC]
First Nationwide Test of the EAS [Official FCC blog]
About the Integrated Public Alert and Warning System (IPAWS) [FEMA]
Feds try to prevent War of the Worlds-style panic over national emergency alert [Ars Technica]