At 2 p.m. EST today, a familiar sound will ring out from TVs across the country.

For the first time ever, the Emergency Alert System will be tested nationwide on all radio and TV channels, including cable and satellite.  The 30-second test will be executed by the FCC, in conjunction with FEMA and the NWS.

“The purpose of the test is to assess the reliability and effectiveness of the EAS as a public alert mechanism,” the FCC stated, saying that they will use “the results of this nationwide test to assess the reliability and effectiveness of the EAS” and “make improvements to the system as appropriate.”

According to the FCC, the President has sole responsibility for determining when the EAS will be activated at the national level.