SEWS Guidelines

The Victorian State Emergency Service has SEWS Guidelines on who can issue an emergency announcement using the Standard Emergency Warning Signal (SEWS) and when. Unfortunately what is lacking is detail of how the message is sent. However, the inclusion of a pro-forma facsimile form suggests that fax is used.

1. The decision to request the use of the Standard Emergency Warning Signal is made by the Incident Controller (or his representative). This is the person who has the responsibility for dealing with the emergency. For example, in a wildfire it would be the CFA or the Department of Natural Resources and Environment; in a wind storm, it would be the State Emergency Service; for a structure fire, it would be the MFB or the CFA; etc.
2. The request is made to the Police Divisional Emergency Response Coordinator, who will issue the Emergency Warning Notice to media organisations. ...

From: SEWS Guidelines, Victorian State Emergency Service (28 November 2006)

See also: SEWS Demo (Audio) from BoM.