Date released: February 16, 2009
Disclaimer: The following information was obtained from the City of Sachse Office of Emergency Managment and modified by Glen Geen/KD5PXO for use here. Italicized text indicates where wording in this document deviates from the original.
To describe the regional guidelines pertaining to use of outdoor warning systems in North Central Texas Area (NCT), and to establish recommendations for their use.
- Outdoor Warning SystemAn Outdoor Warning System (OWS) consists of sirens designed to alert citizens of approaching or existing hazardous conditions which requires immediate protective actions in order to save lives and property. By verbal agreement, the NCT area shall refer to sirens as "Outdoor Warning Systems" in an effort to reinforce the multiple conditions for which communities may sound sirens to alert citizens outdoors.
- Reasons for ActivitationOutdoor warning system are developed to alert and notify citizens outdoors of emergency situations. These situations include are not limited to natural emergencies, transportation accidents involving hazardous materials, emergencies at fixed facilities, acts of terrorism or other catastrophic events in which the community needs to be informed immediately. Citizens indoors should not mistakenly wait to hear a siren as their only source of warning informatin. Siren systems are intended for outdoor notification and may not be heard indoors. A NOAA All Hazards Radio with Specific Area Message Encoding (SAME) technology is a good method of receiving warning messages indoors. Some communities maintain other warning systems to alert citizens indoors.
- Activiation GuidlinesEven though communties vary in specific criteria for activating OWS, there are some commonalities in determining activiation guidelines. The following are factors to consider as minimum activation guidelines:
- The National Weather Server issues a Tornado Warning or Severe Thunderstorm Warning with the phrase "Destructive winds in excess of 70 mph (or higher) are likely with this storm" for you immediate area. A community existing in multiple conties shoul pay close attention to the warning area.
- Trained storm spotters have reported a tornado in the jurisdiction, or in a neighboring jurisdiction that has the potentialto affect your community. (Each community should determine satisfactory methods for verifying tornado activy reports).
- Reported hail of 1.25 inches in diameter or greater. ( 1 inch may be more appropriate for areas or events where large numbers of people are outdoors).
- At the discression of the community's Emergency Manager
- Notification of ActivationA community should make external notifications to neighboring communities as soon as possible indicating the OWS was activated. During RACES nets activiations, the notification may be conducted by making an announcement via the amateur radio net in progress or other means available.
- Monthly testingCommunities in North Central Texas test their Outdoor Warning Sirens (OWS) during the first week of each month based on their testing protocols. Here in Sachse, Tx, we test the Outdoor Warning Systems on the first Saturday of the month. OWS are not tested during periods when severe weather is possible or looks threatening, so as to avoid confusion between actual severe weather and testing.
- ReferencesFederal Emergency Management Agency (FEMA) Outdoor Waring System Guide, CPG1-17R