Ars Technica has a piece on the "first-ever nationwide test of the Emergency Alert System (EAS)," slated for this Wednesday at 2 p.m. EST. An excerpt: "This national system will look and sound much like the current (and local) emergency warnings often seen on TV or heard on radio, but the scope is larger and it can be put under the direct control of the President. The Federal Emergency Management Agency (FEMA), the Federal Communications Commission (FCC), and the National Weather Service (NWS) will all coordinate the test, but it's FEMA that actually transmits the alert code. Concerned that such a test might alarm people, the agencies are going to extraordinary lengths to provide a heads-up. I first heard about the test in an e-mail newsletter from my city government, which told residents last week, 'Do not be alarmed when an emergency message will take over the airways... this is only a test.' The test will display a warning message on TV screens, though as my city helpfully noted, 'Due to some technical limitations, a visual message indicating that "this is a test" may not pop up on every TV channel, especially where people use cable to receive their television stations.'"