City of Melissa Outdoor Warning Siren System 

Within the City of Melissa five strategically located sirens operate together when activated, sending a warning signal to anyone outdoors, that danger is imminent, and cover should be sought immediately.  

The sirens are designed to provide warnings for persons who are outdoors.  They do not send information through any other means and will not provide any additional information to those persons who are indoors.  The City of Melissa operates a Code Red call system, which while not directly tied to the outdoor warning sirens, will often work in tandem with the sirens.

When the National Weather Service (NWS) detects a storm or other weather event that can pose a danger to residents, it will create a geographical warning for affected areas, called a polygon, and place these over an area map.  Should any portion of the polygon encompass one or more of the five Melissa siren locations, all sirens will be activated.

The shape and size of these overlay polygons vary with each storm and can change as the storm system or weather event changes or moves.

The sirens will become active when at least one of the sirens falls within the polygon configuration overlay when:

• the NWS issues a Tornado Warning for Collin County naming Melissa in the path;
• trained storm spotters have reported a tornado in the jurisdiction, or in a neighboring jurisdiction that has the potential to affect the Melissa area;
• other emergencies as directed by the community’s designated public safety officials.

Testing of the sirens will take place on a regular basis to monitor all components of the system and exercise the infrastructure to keep it in good working condition.  These tests include:

• Daily – a silent test will be conducted at a determined time to ensure continued connectivity;
• Monthly – a voice test message followed by 30 seconds of wail tone will be sounded on the first Saturday of each month at noon.

Occasionally, Melissa residents may hear the outdoor warning sirens from neighboring communities.   This may happen if the NWS polygon overlay includes their community but not Melissa, or that community uses different criteria to activate their systems, or their sirens are tested on a schedule different than Melissa’s.

For more information or questions, please contact Fire Chief Carl Nix or 972-838-1383.