On Wednesday, Oct. 3, starting at approximately 2:20 p.m. EDT, FEMA will conduct the first-ever nationwide test of the Wireless Emergency Alert (WEA) and Emergency Alert System (EAS) to test national warning capabilities. The test message will be sent to all radio, TV, and participating wireless carriers. Cell phones will buzz and make a loud tone. During this time, cell phones that are switched on, within range of an active cell tower, and whose wireless carrier participates in WEAs, should receive the test message.
Please see the below video for more: