Major information about the test includes:
The purpose of the Aug. 11 test is to ensure that the EAS and WEA systems continue to be effective means of warning the public about emergencies, particularly those on the national level. Periodic testing of public alert and warning systems helps to assess the operational readiness of alerting infrastructure and to identify any needed technological and administrative improvements.
The WEA portion of the test will be initiated using FEMA’s Integrated Public Alert and Warning System (IPAWS), a centralized internet-based system administered by FEMA that enables authorities to send authenticated emergency messages to the public through multiple communications networks. The WEA test will be administered via a code that alerts only phones that have opted in to receive WEA test messages. The EAS portion of the test will be initiated using FEMA-designated Primary Entry Point stations.
In case the Aug. 11 test is canceled due to widespread severe weather or other significant events, a back-up testing date is scheduled for Aug. 25.
https://www.hastingsgov.org/home/news/fema-and-fcc-plan-nationwide-emergency-alert-test-wednesday-august-11-2021-220pm-test