Skip to main content Skip to footer

Emergency Alerts

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.

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.

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, AMBER Alerts, and local emergency alerts for hazmat emergencies or active law enforcement incidents. While these are often targeted to a specific area, technology limitations commonly result in over-alerting.

FEMA's Wireless Emergency Alerts

FCC Consumer Guidance on Wireless Emergency 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 and public AlertSense subscribers by the Waukesha County Communications Center. As landlines become less common, Wireless Emergency Alerts are taking precedence over “Reverse 911s.” 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.

You can sign up for Waukesha County Alerts online to receive ETN Alerts via your cell phone or email.

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.

FEMA's Emergency Alert System

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.

National Weather Service (NWS) - NOAA Weather Radio Information

Initially designed for wartime and civil defense alerts, outdoor warning sirens have transitioned from their original purpose during World War II and the Cold War; now serving primarily as critical alerts for natural disasters, and several types of dangers. Outdoor warning sirens are intended to warn the public to take immediate life-saving actions. A memorable slogan when an outdoor warning siren is activated is to, "Get Inside, Get Information". Outdoor warning sirens are not simply "tornado sirens", sirens may be used for all types of hazards.

 Local municipalities are responsible for the installation and maintenance of outdoor warning sirens. The Waukesha County Communications Center is responsible for the activations of the Outdoor Warning Siren System for the following communities: 

  • Village of Big Bend
  • Town of Brookfield
  • Village of Butler
  • Village of Eagle
  • Village of Menomonee Falls
  • Village of Merton
  • Unincorporated North Lake
  • Village of Pewaukee
  • Unincorporated Stone Bank
  • Village of Sussex

National Weather Service (NWS) - Outdoor Warning Sirens: Frequently Asked Questions

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.

Frequently Asked Questions

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 cell phones automatically filter out alerts that the subscriber is not impacted by.

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 PBS’s WARN map. You can also view the alert history on some mobile devices by accessing Wireless Emergency Alerts in the settings.

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. 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. Still, please understand that in times of widespread or high-priority incidents, first responders and telecommunicators may be focused on helping people in crisis.

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.

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.

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. 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.

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.

This website uses cookies to enhance usability and provide you with a more personal experience. By using this website, you agree to our use of cookies as explained in our Privacy Policy.