Outdoor Warning Siren System Operational

The recently installed outdoor warning siren system in Melissa is now operational.  The five strategically-placed 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 pattern overlays for affected areas, called polygon configurations, and place these over an area map. Should any portion of these overlays lie atop one or more of the five Melissa siren locations, that siren will be activated, and since all five work together, all will activate.   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;
• the NWS issues a Severe Thunderstorm Warning and indicates the potential for destructive winds of 70 mph or greater potentially affecting the Melissa area;
• trained storm spotters have reported a tornado in the jurisdiction, or in a neighboring jurisdiction that has the potential to affect the Melissa area;
• hail of 1.5” in diameter or greater is observed. The size of hail that warrants system activation may be adjusted at the discretion of local officials in the event of special situations such as large outdoor public gatherings where the potential for injury is increased; and 
• other emergency 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;
• Weekly – a 10-second alert blast will be sounded every Wednesday of the month at noon; and
• Monthly – a three-minute continuous wail 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 Harold Watkins, Jr.  or 972-838-1081.