A national emergency alert test will blare out across the U.S. this week. According to FEMA, every TV, radio and cellphone will be interrupted with an emergency message at 2:20 p.m. Eastern time on Wednesday. The test is scheduled to last approximately one minute. Officials say the alert is similar to that of an Amber Alert or warnings issued by the National Weather Service. The alert is being issued because federal emergency management coordinators need to make sure the system is still an effective way to warn Americans about emergencies