Wireless Emergency Alerts - Prepare Metro KC

Cell tower geography may lead to temporary overwarningBecause cell towers broadcast in aradius, or circle, their coverage areasdon’t line up neatly with countyboundaries. This means you may receivewarnings for an adjacent county if you’rewithin a few miles of the border.The alerts are delivered directly fromcell tower to cell phone through a onewaybroadcast. The Commercial MobileAlert System does not track or locateindividual cell phones or phone numbers— it simply broadcasts to all phoneswithin range. Unfortunately, in somecases, this may result in overwarning.For example, if a tornado warningis issued for a particular county,it will go to all towers that servethat county. Towers in urban areasgenerally serve a radius of two to fivemiles, and in rural areas up to 10 miles,so the warning message may reach alittle beyond the warning boundaries.Technicians will work to solveoverwarning problems, and residents areasked to be patient as adjustments aremade to the new system.As this simplified illustration shows, whena warning is issued for County 1, peoplein County 2 and County 3 who are withinrange of a tower that servesthe warned county willCOUNTY 2also get the message.COUNTY 1In reality, there are hundredsof towers with overlappingservice areas throughout theKansas City area.COUNTY 3Wireless Emergency Alerts: Three Types of WarningsThe Commercial Mobile Alert System (CMAS)can be used to broadcast three types ofemergency alerts:OOPRESIDENTIAL ALERTS — Issued by theU.S. President in the event of a nationwideemergency.OOIMMINENT THREAT ALERTS — Typicallyissued by the National Weather Service; inthe Kansas City metropolitan area, thesewould include tornado, flash flooding, icestorm and blizzard warnings.OOAMBER ALERTS — Issued by lawenforcement to share information about achild abduction.No president has ever yet had to issue apresidential alert, but should one becomenecessary, cell phone providers are required tobroadcast it to all WEA-capable phones.Cell phone users may choose to opt out ofimminent threat and/or AMBER alerts, but theprocedures vary by carrier. Some providerswill allow customers to opt out of one or theother, while others only allow you to opt out ofboth. Contact your wireless provider for moreinformation.The Metropolitan Emergency Managers Committeestrongly encourages all residents not to opt out ofthese potentially life-saving messages.To learn more, contact your local emergency management office or wireless service provider.Visit www.preparemetrokc.org for more information on emergency preparedness.