Brace yourself. You should hear an emergency alert at 1:55 Wednesday afternoon.

This is a Canada-wide test of the National Public Alerting System that is being distributed across radio, television, and compatible cellular devices.

It will begin with an alert tone, followed by a message letting you know that it's a test and doesn't require any action.

⚠️ We're running a routine test on November 17 ⚠️

Canadians in participating provinces and territories can expect an alert on their TV, phone, & radio. For a list of times, visit https://t.co/nopJwwkXRJ. #AlertReadyTest pic.twitter.com/vQziq10vlQ

— Alert Ready (@AlertReady) November 12, 2021

British Columbia and the Northwest Territories won't be taking part in the test.

The Alert Ready website states: "The Alert Ready system was developed with many partners, including federal, provincial and territorial emergency management officials, Environment and Climate Change Canada, Pelmorex, the broadcasting industry and wireless service providers. Together, these partners work to ensure Canadians receive alerts immediately and know when to take action to stay safe."