UPDATE: The IPAWS national test of emergency alert systems has been postponed to Oct. 3 at 2:18 p.m. EDT, due to the response effort that continues in the wake of Hurricane Florence, FEMA said in an updated statement this week.

Read the original story below:

While President Donald Trump is known for his frequent use of Twitter, on Thursday, an alert on his behalf will be sent to cellphones nationwide.

>> Read more trending news

The Federal Emergency Management Agency in coordination with the Federal Communications Commission will conduct the IPAWS national test of the Emergency Alert System and Wireless Emergency Alerts on Sept. 20, according to a FEMA news release. The WEA portion of the test commences at 2:18 p.m. EDT, and the EAS portion follows at 2:20 p.m. EDT. 

The test is necessary to assess the operational readiness of the national message distribution system and to determine if improvements are needed, FEMA said.

The EAS is a national public warning system that provides the president with the communications capability to address the nation during a national emergency. The WEA system is used to warn the public about dangerous weather, missing children and other critical situations through alerts transmitted to cellphones.

The national test will use the same tone and vibration that accompany all WEA messages, such as tornado warnings and Amber Alerts. The EAS message will include the following information:

"THIS IS A TEST of the National Emergency Alert System. This system was developed by broadcast and cable operators in voluntary cooperation with the Federal Emergency Management Agency, the Federal Communications Commission, and local authorities to keep you informed in the event of an emergency. If this had been an actual emergency an official message would have followed the tone alert you heard at the start of this message. A similar wireless emergency alert test message has been sent to all cellphones nationwide. Some cell phones will receive the message; others will not. No action is required."

The WEA test message will have a header that reads "Presidential Alert" and text that says: "THIS IS A TEST of the National Wireless Emergency Alert System. No action is needed."

Users cannot opt out of the WEA test.

FEMA said that users may opt of receiving alerts in the imminent threat and Amber categories but cannot opt out of receiving presidential alerts.

If a real-life event causes the IPAWS national test to be postponed, the backup testing date is Oct. 3.

The IPAWS National Test for emergency alert systems takes place Sept. 20, 2018.

Credit: FEMA

icon to expand image

Credit: FEMA