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Summary of Public Warning Systems

Overview of Public Warning Issues and Solutions

Kendall Post (ALERT Systems, Madison WI, Tel: 608-222-1303)

Scientists and engineers have made great strides in weather radar and some other early-warning methods. Forecasting offices routinely issue early warnings of natural calamities that have led to significantly reduced casualties and injuries. But issuing warnings is not the same as delivering warnings. After the Oklahoma City tornado of May 3, 1999, for example, when warnings had been widely broadcast, a woman interviewed on National television while standing in front of the remnants of her home said she didn't know of the threat until she heard the roar outside. Warning systems today do not warn enough of the people at risk and often warn many people not at risk.

The delivery of warnings is even more problematic when the threat is not obvious to the people at risk. Some threats provide no easily discernable precursor as in the case of terrorism. The systems and tools available to local emergency managers for these situations are wholly inadequate and rudimentary at best. The consequences especially in bio- or radiological terrorism can be staggering.

The question is where do we begin to solve these and related public warning system problems? Who will lead the search for solutions since the problem is national and beyond the scope of any one level of government? How do we craft a common vision that satisfies all stakeholders with public safety and homeland security obligations or interests?

This document introduces the problems, the consequences of the problems and the solutions.


Emergency management is first and foremost a problem of information assimilation, management and dissemination under stress. It's all about getting the right information from the right source to the right people at the right time so everyone makes the right decision.

The right people may be the general public, special emergency response teams, the media, utility managers or auxiliary teams like the Red Cross. They may be local or resources from federal, state or neighboring area agencies. They may be people with special resources such as heavy construction equipment, damage assessment satellites, or chemical decontamination equipment. They may be people that can fill sandbags, or have medical or search and rescue skills. The right people are just those affected by or involved in the situation so as not to attract sightseers while response teams are trying to get on site.

The right information for each of these audiences varies in location. People north of a chemical plant may need to evacuate by one road while those south of the plant may need to use another route. People further from the situation may need to shelter-in-place—close windows, turn-off air-conditioners, and stay indoors. People with respiratory conditions or other limitations may need special advisories. Response teams may need to assemble at one of several staging areas.

The right source in a myriad of sensor data and human intelligence assembled to produce accurate conclusions. This information arrives through an array of federal, state, local and private sector channels. As such, the public warning system is far more than the “last mile” systems of sirens, the radio/TV EAS, and weather radios. The right source varies with threat. The threat may be generally understood as in the case of a tornado except for the path and severity. In the case of train derailments involving complex mixes of hazardous materials, emergency managers need wind speed, humidity, topological and access road maps, population density, tank capacity and fullness, antidotes and information from many other sources. The right sources in cases of domestic terrorism involving unknown biological agents is also a long list but difficult to gather.

The right time varies with the type of crisis. After earthquakes and most wide area events, the right time is immediately before people with good intentions flood 911 centers with non-essential calls that hinder mobilization efforts. In some cases like hurricanes, people may need to be evacuated in stages to minimize highway congestion. In chemical fires, those in greatest danger need to be moved first. The right time is well before and long after the onset of crises. It encompasses times needed for training exercises, system testing, response mobilization and disaster recovery.

The 5 right, R5 processes occur at local, state and federal levels of government to some degree. All of this activity must be accomplished in a minimum amount of time with a minimum of staff in crises. It must be done with the barest of communications and utility resources remaining after disasters.

Ultimately, R5 processes manifest themselves as public warnings, interagency notification and mobilization activities, and other disaster response and recovery efforts.

The General State of the Emergency Information Chain that Provides Public Warnings

A few parts of the emergency information chain are relatively sophisticated and effective. Scientists and engineers have steadily improved the systems and science for producing early indications of natural calamities. The early issuance of tornado and other weather warnings has significantly reduced casualties and injuries.

Other parts of the information chain are under-funded and highly problematic. This is particularly true at the local agency level of the public warning chain. Local agencies are focal points in crises. They bear the critical burden of first responders. But while they greatly outnumber federal and state agencies, their problems and needs are generally under-represented in federal studies, policy and technical reports, and national forums.

The “last mile” public warning systems available to emergency managers date from the 1950s. Information handling and dissemination tools of local agencies are rudimentary at best. As such, local agencies are bottlenecks in the vital information chain during crises.

The overall public warning chain is incomplete and highly fragmented. As such, the delivery of vital information and other emergency communications can be very slow and unreliable. When threats provide no easily discernable pre-cursor (terrorism) or do not themselves heighten public awareness (color of sky) or are dynamic, warning and mobilization problems compound very rapidly.

To further improve the effectiveness and timeliness of public warnings and other disaster response activities, warning systems will have to be coupled directly to computer threat modeling, early warning sensors and other advanced tools upstream in the information chain. But existing systems were not designed to interface with computers and modern tools. To activate weather radio, the EAS system or telephone auto-dialer systems, most local emergency management agencies have to phone the warning to intermediaries like the regional weather office or EAS TV hub station. This information relay process invites human errors and contributes delays. When the crisis is dynamic, this relay chain is very cumbersome. The disconnect between warning systems and the upstream information processes has helped discourage the development and deployment of new emergency management tools for decades.

The Information Assimilation Problem of Public Warnings

Emergency managers (EMs) need information to issue credible public warnings and to focus response efforts effectively during crises. That information varies by type of the crisis but gathering and assessing it inevitably delays warnings and mobilization efforts to some degree. In tornado situations, weather forecasting offices generally convey tornado location and other information seen on their computer terminals to local emergency officials verbally by phone or radio. Local EMs then translate this verbal description to maps, paper and dispatch radio messages to guide public alerting, interagency notification and response mobilization activities. This relay process invites human errors and delays warnings.

The danger posed by threats like tornadoes are obvious and relatively easy to visualize. EMs generally know the geographic area described by the forecasting office. But other situations like train derailments demand a large array of information to assess the scope of the threat and to make credible decisions. EMs need wind, humidity and rainfall rate, tank car contents and capacity, toxicity information, decontamination procedures, antidotes for response personnel, and the availability of neutralizing materials to deal with the threat. With existing systems, gathering this information may take hours. As a result, EMs often have to assume the very worst. They have to dramatically expand evacuation areas, and response and mobilization efforts. Expanded evacuations are often unnecessary hardships for the elderly and the infirm, and they’re expensive for businesses. Some terrorism scenarios have similar information demands and far greater consequences.

Some crises like terrorism offer no easily discernable precursor. Data mining software and threat-recognition tools exist but to be effective they need a lot of diverse information. Unfortunately, this information arrives by every conceivable means – phone, fax, pager, satellite feed, email, National Guard terminals, highway network, and couriers including state patrol officers. Every information source has its own protocols, formats and priority codes. With data in so many forms, advanced computer-aided methods have little value. Results are too slow to preempt or blunt the impact in most situations.

Information channels are unreliable. Information is sometimes lost because of the information fragmentation problem described in the previous paragraph. Some information dissemination systems have no means of confirming vital information ever reached the appropriate duty personnel.

When crises are dynamic like wind driven industrial chemical fires or radiological terrorism, information assimilation issues are far more complex and often completely impossible. “We are reduced to nothing more than educated guesses.”

The Information Management Problem of Public Warnings

For direct public warnings, evacuations and other disaster response activities with maximum effectiveness, emergency managers need to manage information so as to visualize the situation, preferably in real-time. Geographic Information Systems are ideal visualization tools but few local agencies have the budgets or manpower to access and maintain the underlying spatial databases.

Some spatial databases like maps, population density and demographic data can be pre-positioned at local emergency management agencies. Entire regional libraries could be provided with a few compact disks. But tornado path, rainfall in watershed area and other dynamic information is often needed first to assess or model damage and delineate affected areas. The information assimilation problem of public warning activities must be solved to resolve information management for decision-making purposes.

Computer-aided modeling software modules need to be added to the GIS to visualize bio- or radiological terrorism and other situations that are driven by dynamic factors like wind and rain. Modeled results need to be map overlays that can then be used to guide public warnings and other response activities. But there is little incentive to develop or master such tools when information assimilation and database management problems preclude results in anything close to real-time.

The information management problem becomes more difficult when aerial photos and infrared imagery from satellites need to be fused with other spatial information. Images need to be scaled and adjusted for the warp of the earth’s surface and the camera’s viewing angle.

The Information Dissemination Problem of Public Warnings

Public warning and other emergency information dissemination problems can be grouped into accessibility, strategic messaging and miscellaneous categories. Information delivery problems cause EMs to compensate with door-to-door evacuations, the assembly of large staging areas to coordinate responses and other labor-intensive efforts. These efforts keep people at risk for longer periods of time, divert manpower at critical times and allow crises to expand.

Accessibility of People

New building construction methods, Satellite TV, and public mobility are all undermining the effectiveness of existing “last mile” public warning systems. When the color of the sky does not pre-sensitize people to the threat of severe weather, when the threat is colorless or odorless, and when people are asleep, accessibility is especially problematic. The author’s firm surveyed EMs with jurisdictions of 5.5M people, asking them to estimate what percentage of the public could they alert to a major threat within 15 minutes. Using all systems at their disposal, they estimated 23% at 3AM and perhaps 40% at 10AM. Accessibility to people falls quickly when AC power fails. People who are deaf and hard-of-hearing, staying in hotels or camping, living in rural areas, working in factories and shopping in malls are unreachable on short notice with any certainty.

Strategic Messaging

In many crises including terrorism, warnings need to be tailored for specific geographic areas and audiences. But existing public warning systems are either not strategic or where partially strategic not fast enough. EMs cannot reliably deliver evacuation orders and route information to only those households north of an industrial chemical fire without that message also being heard by people south of the plant. Inevitably, some people south of the plant become confused by too much information and evacuate through the plume cloud before officials can erect barriers.

The geographic specificity of information is often lost when broadcast on short notice by radio and TV. Even when specific information is broadcast, some people cannot visualize geographic information when conveyed verbally. As a result, people who would be better off sheltering-in-place – closing windows, turning-off air-conditioners and staying indoors – evacuate increasing their risk.

Existing public warning systems are not geographically or audience specific enough to use for lost child or Alzheimer patient, “funny money” passing, hostage, or school shooting situations. EMs need to be able to stage evacuations in hurricanes and terrorism events according to risk and to avoid highway gridlock. But with existing system, they cannot fully control the time at which people in specific geographic areas receive messages.

Wide-area public warnings have unintended consequences that consume EM energies delaying response efforts. People unaffected by the situation often flood 911 centers with non-essential questions, status requests and other information. Sightseers clog roads impeding response vehicles and evacuations.

Accessibility and Strategic Messaging Together

Together, the accessibility and strategic messaging limitations of existing systems and tools cripple mobilization efforts. Responses to major forest fires that can double every 20 minutes now take 6 hours. Mobilization of building inspectors after the most recent Seattle earthquake took 30 hours. The National Guard needs 1-day to assemble 65% of a unit and 3-days to reach 95%. On weekends and during government administration changes, these times balloon.


Public alerting, interagency notification, response mobilization and associated decision making are interwoven activities. Problems in these areas must be addressed and solved together because they are so interwoven. Problems of any aspect of these activities delay and magnify other efforts.

Basic procedures at the onset of relatively common events like tornadoes already run 10 to 18 minutes. In recent years, county sirens have activated as much as 7 minutes after the tornado leveled the first town in the county. These times balloon when utilities and critical resources collapse.

Cell [phone] broadcasting, satellite radio, intelligent highway and other new civilian alerting methods need to be incorporated into public warning processes but they will further complicate and slow warnings without the integration of systems and development of new tools.

Existing public warning systems have limited self-testing capabilities. To fully test sirens, local officials have to schedule people to listen to each siren. To fully test telephone auto-dialer systems, local officials have to disturb many households. Radio/TV and weather radio alarm tests are inseparable from actual events. They irritate or awaken people so they cannot be run too often. Existing systems can and do fail unnoticed until critical times. The tone activation generator in the weather radio transmitter serving the Alba River areas of Georgia and Alabama went un-noticed until well into the large flood of 1998.

Access to existing public warning systems is indirect and subject to the availability of intermediaries. A 1999 evacuation drill at 3-Mile Island nuclear power plant failed in part because the engineer at the EAS hub station went home at 11PM, the end of his shift.

Public warning system performance is summarized on the next page.

Other Factors in Public Warnings

Experienced incident commanders and local emergency managers cite a number of non-communications issues with impact on public warnings:


Federal agencies tend to mitigate every hazard individually with single purpose solutions while local agencies have all-hazard missions. For budgetary, training and other reasons, they need all-hazard solutions. Their information needs, and public warning and response efforts are generally the same whether the situation involves a chemical spill due to a train derailment, a major chemical plant fire or a terrorist attack with a chemical weapon. Only the magnitude of the event and their response efforts are different.

Fragmentation and gaps in the public warning communications chain cause human errors and delays. The consequences and responsibility for these errors and delays often fall on local agencies.

Economic Issues

Local agencies suffer financial death by a thousand small cuts. Many mitigation programs provide single-purpose “one-shot” grants but local agencies have to deal with ongoing training, recurring maintenance and rapid obsolescence.

There are more than 13,000 public safety access points (PSAPs) so the total cost of these “thousands of small cuts” is enormous. It’s a vast unnecessary hidden burden on taxpayers.

Summary Comparison of Public Warning Systems

Additional Notes

Outdoor Sirens:

Radio/TV EAS:

Weather Radio (NOAA):

Telephone Ring-Down:

Belt Pager for Deaf (Not shown)

Issues Extd Caller ID Tel Ring Down Weather Radio      Sirens      Radio/TV EAS
All Hazard Types          
All Hazard Sizes          
All Hazard Phases          
100% Coverage          
No User Fees          
Easy to Use by Public          
Lightens 911 Load          
Alarm Speed          
Awakens At Night          
Alerts Deaf & HH          
Alerts Rural Residents          
Alerts Those Affected          
Distinguishes Urgency Immediately          
Delivers Situation          
Delivers Response          
Message Replay          
Direct to Public          
Not Affect by Weather          
Multi-lingual       n/a  
AC Power Required          
Constant Self Testing          
Economical Solution          
Response Lead time          


  Yes or Good
  Partial or Imperfect or Sometimes
  No or Problematic

Local agencies can’t participate in all discrete programs. The overhead and manpower associated with locating, applying and managing many funding streams and programs is too high.

911 center work is stressful so personnel turn-over is high. Single function mitigation tools and systems are contributing factors. 100-year flood and other rarely used single purpose tools complicate training and lengthen training time. Both commanders and trainees fear they’ll not remember how to use these tools in crises. These feelings add to stress levels and turn-over rates.

Funding priorities

Local appropriations bodies first spend money on equipment for small everyday-crises before they fund large-crisis systems. They expect state and federal government help with 100-year flood and other rare large events so they see these tools as state and federal matters. Since systems like weather radio are not suited to lost child, hostage, hazmat spills or other common small crises, they aren't funding priorities until after catastrophes.


Local officials need integrated all-hazard systems and tools for readiness reasons. Tools that can be used in everyday events will be used regularly so system operators will be proficient at the onset of major crises. But fully integrated tools for information assimilation, management and dissemination processes do not exist.

Cost Sharing

Cost apportionment formulas for public warning infrastructure are needed. All public warning and interagency notification and mobilization infrastructure has both national security and local public safety functions. Lands under multiple federal, state, American-Indian, and local jurisdictions are often interwoven. But responsibility for public warnings in these jurisdictions often falls to the one agency in the area that has a 24/7 operations center.

Local emergency management agencies are often physically the closest authorities to early-warning sensors like flood gages. They are the logical overseers and maintainers of new biological and radiological weapons monitors.

Technology Issues

Technology is advancing at a pace that exceeds the skills of many local emergency management agencies and private sector providers. It is not uncommon to see emergency managers wearing multiple pagers because they don’t have local firms with the knowledge or equipment to configure pagers for multiple channels.

Public Expectations

Expectations about response and recovery efforts are being heightened by widespread usage of cell-phones, the Internet, CNN and other "instantaneous" communications channels.

Program & Policy Influence

Federal reports and policies talk about State and local partners but programs routinely overlook or give little weight to the operational realities, problems and needs of those partners.

1st response agencies should have a major voice in the development of new systems and methods. “Our necks are on the line." "We’re not technology gurus but we do know what will and will not work when we see it.”

"We need political top cover to speak freely about the issues without suffering career repercussions." "Our 1st objective in major crises is to maintain confidence in government. Talking publicly about systemic problems does not engender this trust."

The Consequences of Public Warning Problems

The consequences of the problems above are measured in human casualties, disaster recovery times and costs, business survival rates, economic activity losses, environmental damage, social repercussions and other ways. By any measure, they're substantial. Consider the value of a 1% reduction in the consequences associated with the following:

September 11th is now expected to have had a $639B impact on the nation after 5 years. Obviously, to deter or blunt just one such attack has immense value.

The Solution of Public Warnings Problems

The historical barriers to infrastructure modernization are public policy, technical, and funding.

The Public Policy / Federalism Barrier and Solution

The U.S. Constitution assigns national security matters to the Federal government. Other authority including public safety is left to States. States further distribute much of their public safety authority to county and municipal governments. But the infrastructure used for public warning, interagency notification and response mobilization has both national security and local public safety purposes. So while agencies at all levels of government have mandates to protect citizens, no agency has overall authority for this dual mission infrastructure.

For lack of some authority sharing mechanism, emergency infrastructure and operating methods have improved little in 5 decades. The country has few standards and no cohesive technology plan. Without a national plan, every agency has followed a separate path. Congress and state legislatures have no arguments to justify change. Local appropriations bodies have been unwilling to risk new technology. Local officials have had to defend the orthodoxy of existing methods. And the private sector has been reluctant to fund R&D.

On November 29th, 120 leaders from the public and private sectors met in McLean VA to address this issue. They resolved to form the Partnership for Public Warning (PPW) to overcome the Federalism barrier to infrastructure modernization. The PPW mission includes setting national infrastructure and best practices standards, crafting a modern all-hazard national warning system plan, and advising Congress in public warning infrastructure matters.

The PPW is intended to give all stakeholders a voice and equal vote in infrastructure matters. Stakeholders include:

As a body representative of all stakeholders, the PPW is seeking Congressional charter as a Utilized Federal Advisory Committee.

The Office of Homeland Security has embraced a proposal by the PPW to draft the first ever Public Warning Infrastructure Plan for the nation. The National Emergency Management Association has endorsed the PPW and its Plan proposal. Funding is imminent.

Because of September 11th, Washington is ready to accept new policy in public warning matters. Terrorism is no longer a remote theoretical issue but rather a real immediate concern. Agencies with public safety missions and their top officials now live in fear of the political fall-out that would occur if they procrastinate before another major act of terrorism.

The readiness for change became obvious when FEMA, NOAA and other federal agencies signaled their support for PPW’s Public Warning Infrastructure Plan to the Office of Homeland Security within days. Similarly, support for PPW standing as a Federal Advisory Committee has proceeded unchallenged with unprecedented speed.

The willingness of a highly regarded retired FEMA official (pending resolution of a “revolving door” issue) to accept the role of PPW Executive Director is another sign of readiness for public policy change. This individual has great credibility and influence, and many friends in Congress and top levels of federal agencies. (He took a call from the Director of FEMA while sitting next to me at the February PPW Trustees meeting.)

The Technical Barrier and Solution

Experience incident commanders and engineers believe emergency management problems are solvable with the proper application of computer, consumer electronic, wireless communications and Internet technology. Core emergency management activities - information assimilation, management and dissemination - can be built upon proven geographic information system, database management, and unified messaging software. A small technology company in Madison, WI has demonstrated effective strategic messaging and accessibility solutions to public warning and information dissemination problems. In short, there are no longer any technical barriers to infrastructure modernization.

The R&D Funding Barrier and Solution

The terrorist attack of September 11th is already unleashing funding for infrastructure modernization. Federal counter terrorism moneys are expected to jump from $10B to about $35B in 2003. More importantly, a significant portion of this new money is intended for infrastructure. In the private sector, venture capital firms are now looking seriously for emergency management related opportunities.

The nation now needs only one more item to cause all stakeholders with public safety missions and interests to engage in the modernization effort – a coherent national infrastructure plan. People with all stakeholder perspectives must be engaged in the development of the plan. Knowledgeable people in some stakeholder categories are difficult to engage. This is particularly true of local emergency officials whose problems and views are generally under-represented. But they bear the critical 1st response burden and must be given a voice. Engaging them will take special outreach efforts to overcome travel budget limitations, schedules that include on-call status and other constraints.

Because trustees and members of the PPW hold the largest body of knowledge in the subject area, the Office of Homeland Security has invited a PPW proposal to develop the national all-hazard warning system strategy. FEMA and other agencies have signaled support. Funding of the PPW and the National Public Warning Strategy Plan is imminent.

The National All-Hazard Public Warning System Plan

The Plan Committee of the PPW is currently defining the Plan, and considering the logistics of the effort. The Plan is intended to produce performance objectives and metrics by which to gauge various technical solutions.

With no precedent in at least 50 years, the Plan will be a major undertaking. The Plan can be scaled somewhat to available funding but given the consequences of terrorism, the effort should err on the comprehensive side. The effort is expected to involve a core of as many as 20 people plus many contributors from various stakeholder categories.

Some members of the core team will receive at least partial salary compensation and out-of-pocket expenses. Other contributors will not be paid except as follows. The PPW may cover travel expenses for experienced local emergency managers, representatives of disability groups and others with very limited budgets on a case-by-case basis. The Plan development team may wish to pay a small stipend or other token compensation to encourage attendance of regional focus groups and Plan review programs. Several issues in the Plan may require small outside studies and surveys. Plan development efforts are expected to cost upwards of $250K.

The Plan is expected to prompt technology proposals and evaluation efforts that will be measured against performance objectives and metrics in the Plan. The Plan will inevitably lead to standards development efforts, best practices of operation, and major policy recommendations. The PPW hopes to solicit research papers, provide peer review for research, and host R&D efforts. The Plan should be revised periodically, perhaps at 5-year intervals to accommodate technological developments, new incident management philosophies, etc.


The public warning systems and tools available to emergency managers limit their ability to perform their missions. The consequences of these limitations are severe. Modernization is easily justified and technically feasible. The public policy barrier to modernization is being removed. After the events of September 11th , there can be no argument but that the time to act has come.

PPW website at

Summary of Public Warning Systems

For another of Ken Post's excellent papers: Weather Radio Alertingright arrow click here.

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With best regards,

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Brad Dye

P.O. Box 266
Fairfield, IL 62837 USA

Skype: braddye
Telephone/Fax: 618-842-3892
Web: Consulting page

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