Testing, testing. Is this emergency warning system on? We’re about to find out.

The Federal Emergency Management Agency, or FEMA, will later today buzz every television and radio in the U.S. with a test of the Emergency Alert System (EAS).

If you’re watching television or listening to radio at 2:20pm ET (11:20am PT), you’ll see and hear the test message.

“THIS IS A TEST of the National Emergency Alert System,” the message will read. “If this had been an actual emergency an official message would have followed the tone alert you heard at the start of this message. No action is required.”

FEMA’s Emergency Alert System is one of several systems in place to communicate emergency messages to the public on a mass scale.

As mobile devices became more common across the U.S. population than televisions and radios, FEMA began working on the Wireless Emergency System to send notifications to smartphone users. It was designed to allow the sitting president to send a message to all U.S. phones in the event of national emergency. Its first test ran last year after a short delay following Hurricane Florence on the east coast.

Today’s test, however, is to measure the system’s readiness to alert in the absence of cell service or internet connectivity.

“Other radio and television broadcast and cable stations in each state that monitor PEP stations will receive and broadcast the test message so that within minutes the test message should be presented by all radio and television, cable, wireline service providers and direct broadcast satellite service providers nationwide,” said FEMA in a blog post.

The first nationwide test was in 2011. This is the first nationwide test of the system this year, and the fifth test to date.

FEMA just sent a ‘Presidential Alert’ to millions of U.S. phones