Waukesha County

Emergency Alerts

Emergency Alerting is a key component of our communities’ emergency preparedness. Some of the most frequently asked questions we receive are regarding emergency alerts. It is understandable to have questions because there are many kinds of alerts and they frequently involve matters that are critical to safety: both our own, and that of our family and community. This page is dedicated to answering common questions and to providing resources for more information.


Types of Alerts

  • Wireless Emergency Alerts: Wireless Emergency Alerts or WEAs are short emergency messages that are broadcast to cellphones in a specific area. Depending on your cellular device and carrier, a WEA is limited to either 90 or 360 characters. WEAs may include weather warnings and AMBER Alerts, as well as local emergency alerts like those for hazmat emergencies or active law enforcement incidents. While these are often targeted to a specific area, technology limitations commonly result in over-alerting.
  • Emergency Telephone Number Alerts: Emergency Telephone Number or ETN Alerts are more commonly known as “Reverse 911” alerts. These messages are sent to phone numbers included in the white and yellow pages, as well as public AlertSense subscribers by the Waukesha County Communications Center. As landlines become less common, Wireless Emergency Alerts are taking precedence over “Reverse 911s.” To receive ETN Alerts via your cell phone or email, you can sign up online here. Be aware that these alerts are sent by the Waukesha County Communications Center and other Public Safety Answering Points (PSAPs) may not utilize this system.
  • Emergency Alert System: The Emergency Alert System or EAS is the national public warning system that can deliver emergency alerts over the radio, as well as broadcast and cable television. EAS messages may include weather emergencies, Presidential Alerts, AMBER Alerts, and other widespread or high-hazard emergencies.
  • NOAA Weather Radio: The National Oceanic and Atmospheric Administration or NOAA is an alerting partner that sends National Weather Service (NWS) weather alerts over their all-hazards broadcast network. All residents are encouraged to have a NOAA Weather Radio in their home and/or business and to not rely solely on Outdoor Warning Sirens when indoors.
  • Additional Alerts:
    • AMBER Alerts: a child has been abducted and is in imminent danger.
    • Silver Alerts: an elderly, cognitively impaired person is missing.
    • Green Alerts: a veteran is missing and at-risk.
    • Some local communities may have supplemental community alert capabilities not listed here. If you live in a community not serviced by the Waukesha County Communications Center, you can check with your local police department to see if they have different capabilities.


Frequently Asked Questions

  • Why did I receive an alert for an area where I am not located?

Wireless Emergency Alerts (WEAs) are the most common culprit when it comes to over-alerting. Alerting Authorities typically send an alert to a specific geographical area, for example, a half-mile radius around a barricaded gunman, or a 9 square mile polygon around the neighborhood where a missing child was last seen. This is known as “geotargeting” or “geofencing”. Unfortunately, cellular provider technology is not yet capable of matching these boundaries exactly. To comply with federal regulation that ensures no WEA-capable cellphones miss the alerts, cellular carriers err on the side of caution and regularly over-alert. This can result in whole cell-sectors or cell-tower areas being alerted despite the authorities targeting a smaller area. As cellular technology improves over time, this over-alerting will be reduced. Some of the newest cellphones automatically filter out alerts that the subscriber is not impacted by.

  • I received an alert that might affect me, what should I do?

Alerts are limited in the amount of information they can contain. WEAs, for example, are limited to only 90 or 360 characters depending on the recipients’ cellphone and carrier. All alerts should describe the location of, or area impacted by the alert. Nearby recipients should follow the instructions in the alert. Those who are well outside of the alert area should play it safe but may be able to disregard the alert. For example, if an alert says that there is a police incident in your neighborhood and that residents should avoid the area and take shelter in their basement, you should do just that. If the alert is from Menomonee Falls and you are a resident of Waukesha, for example, or another community that is not adjacent, you can likely disregard it. Always err on the side of caution and consider your safety first when evaluating the situation. To view active and historical alerts, including the impacted areas, you can visit https://warn.pbs.org/. You can also view the alert history on some mobile devices by accessing Wireless Emergency Alerts in the settings.

  • I have questions about an alert, where can I find more information?

To view active, expired, and canceled Wireless Emergency Alerts, EAS, and weather warnings, including their message content and the intended alert area, you can visit PBS’s WARN map here: https://warn.pbs.org/. The map can be used to confirm or rule out whether your area is impacted. You can also check your local police and fire departments’ websites or social media accounts. Lastly, you can call your local police or fire department for more information, but please understand that in times of widespread or high-priority incidents, first-responders and telecommunicators may be focused on helping people in crisis.

  • Who sends out these alerts?

Different alerts come from different sources, but all are verified Alerting Authorities. Local alerts such as Wireless Emergency Alerts and Emergency Telephone Number (ETN) alerts are sent by Waukesha County on behalf of local law enforcement and fire departments. Emergency Alert System or EAS messages can be issued by local authorities, Waukesha County, Wisconsin Emergency Management, and federal partners such as the National Weather Service. For Presidential Alerts during national emergencies, these broadcasts may be issued by the President.

  • Do Emergency Alerts track my location?

No, Wireless Emergency Alerts and other types of alerts do not track individuals’ locations. This is one of the reasons why people outside of an impacted area receive alerts that are not relevant to them. Alerting Authorities, as well as cellular providers, do not track or collect specific location data. The cellular companies push out alerts based on the cell-tower that a subscriber has most recently connected to.

  • How can I ensure that I receive alerts for my area?

Federal mandates ensure that nearly all Wireless Emergency Alert capable cellphones receive alerts for their area. To ensure that your phone has alerts enabled you should check with your cellular carrier for instructions on accessing the Wireless Emergency Alerts in your phone’s settings. For “Reverse 911” or ETN alerts, if you do not have a white or yellow pages listed landline, you can sign up for mobile and/or email alerts online here. Lastly, all Waukesha County residents are encouraged to have a NOAA Weather Radio in their home and/or business and to not rely solely on Outdoor Warning Sirens when indoors.

  • How can I disable Wireless Emergency Alerts?

Your wireless carrier may allow you to block certain alerts involving imminent threats and/or AMBER Alerts. If you wish to disable certain Wireless Emergency Alerts you should check with your cellular carrier for instructions on how to change these settings on your mobile device. Consumers cannot block emergency alerts issued by the President. While these alerts can sometimes seem like a nuisance, remember that they’re an integral part of community preparedness, and may provide information that is crucial to your safety or that of your family.


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