Best Practices for the Dissemination of Weather Warnings to the Public

A Best Practice Statement of the American Meteorological Society
(Adopted by the AMS Council 7 January 2018)


Historically the delivery of emergency messages to the public was primarily through broadcast media and NOAA Weather Radio. With the growth in smart technology and social media there has been a proliferation in methods for delivering emergency weather information. Providers of emergency weather communication services range from governmental to media outlets to private-sector individuals. While these services provide valuable communication improvements to the warning system, there are no enterprise-wide established guidelines in place to ensure that the services provided are timely and accurate. These Best Practices represent the next step in encouraging the continued collaboration and cooperation between the various sectors of America’s Weather, Water, and Climate Enterprise to ensure the public receives the highest quality warnings.


The best practices are  intended to be for the benefit of the public; thus, the audience includes the general public as well as providers of weather alerting services, both public and private sector.

Best Practice characteristics

One of the most important roles of the weather enterprise is to provide timely and accurate warnings to the public.  The public is far better off today in receiving warnings than they were 20 years ago, when the only way to receive a warning was via radio, television, or sirens. The many new ways to receive warnings offer tremendous upside so long as information remains coordinated. In most cases, the National Weather Service (NWS) produces and issues warnings through various dissemination channels and the private sector also disseminates or communicates those warnings to the public.  Because of the short-term nature of many warnings and the associated imminent hazardous weather, it is of great importance that NWS warnings are relayed to the public in as timely a fashion as possible and that the warnings are for the same geographic location warned by the NWS. While it is important that all warnings are actually relayed to the public, users can be given the ability to filter warnings to those most appropriate for their use

The National Weather Service is the official government source for weather warnings. Many private-sector weather information companies produce their own warnings in addition to relaying government warnings.  Guidelines for adding distinctiveness between public-sector and private-sector warning messages are addressed below.

Any company or organization that disseminates NWS warnings to the public via web pages, e-mail, telephone, push notification to mobile devices, SMS text messages, or other means should take care to ensure that those warnings are provided from an infrastructure that can handle the number of alerts that must be sent to the consuming public.  Caution must be used to adapt quickly when a particular technology can no longer guarantee successful dissemination of warnings.  Care must also be taken to ensure that all NWS warnings are received from the NWS and decoded in a timely manner.

Specific Best Practices:

  1. Redundancy for Receiving Warnings: Companies disseminating NWS weather warning information should have redundant means of receiving that information.  It is a best practice to utilize at least two, and preferably three, different paths to receive the NWS warnings (e.g., internet and phone lines).
  2. Robustness of the Core Computing Infrastructure: It is crucial that the NWS, as well as any company receiving a warning from the NWS with the intent of relaying it to the public, has enough computing power and communication bandwidth to produce the warning, receive the warning, decode it, determine who should receive the alert and how they should receive it, and then send those alerts to those people or organizations in a timely manner. NWS should also emphasize internal quality control processes to quickly identify and correct any issues with warning product generation and dissemination.

Of particular concern are occasions when hazardous weather occurs over large areas simultaneously.  In such cases, companies that disseminate warnings may experience volumes of alerts that are much higher than that of an average day.  Yet these are the same days when receiving weather alerts is especially critical.  Thus, it is a best practice to have a fully redundant computing and communication capability that can handle a significantly enhanced volume of in-bound and outbound warnings that is handled on an average day.  To ensure timeliness, the computing infrastructure should have the capability to disseminate all warnings to the public within 2 minutes of receipt from the NWS in peak scenarios. 

  1. Reliability and Redundancy of the Core Computing Infrastructure: The computing and telecommunication infrastructure described in Section 2 needs to be redundant and reliable.  Best practice is to have an infrastructure that is at least doubly redundant, preferably triply, for core functions such as power, internet communication, cooling, and telephony among other capabilities.  The complete computing and telecommunication solution should, at a minimum, achieve extreme reliability of uptime and meet the standards listed in Section 2.
  2. Reliability and Redundancy of Message Dissemination: Users and clients should rely on more than one type of technology, to avoid issues of latency in transmission if one particular technology fails.

Therefore, applications that distribute warning information should have the capability to use at least two, and preferably three, distinctive methods to disseminate the message to its user.  Examples of such methods may include an SMS message broker to ensure SMS messages are sent in a timely fashion along with emails, push notifications to a mobile application, phone calls, or cell broadcasts.

Cellular providers should work closely with America’s Weather, Water, and Climate Enterprise to explore better capabilities to distribute life- and property-threatening information to the public.

  1. Geolocation, Naming and Wording Fidelity: When sending alerts that contain NWS warnings to the public, it is important that the consumer receives information that is consistent with the original warning and its intent. 
    1. Warnings should only be sent to users that are physically within the geographic area (polygon whenever possible) as defined by the NWS warning.  Users should also have the ability to receive warnings for areas other than their own location, for which they are responsible for monitoring. Alternatively, any message sent to users outside of the NWS- defined geographic area (i.e., polygon, zone) should clearly alert the receiving party that their location is not within the warning. 
    2. All warnings that originate from the NWS should clearly state that they come from the NWS. All warnings generated by the private sector should be clearly marked so that the user understands who generated it. It is recognized that warnings generated by the private sector are not all based on NWS warnings, and can be tailored and customized for individual clients and their specific needs. Wherever possible, value-added information to an NWS warning should be provided within the private-sector warning message, allowing a more integrated, value-added service.
    3. All warning messages should have a clear date/time stamp on the message to ensure fidelity of timeliness.
    4. All warning messages, regardless of issuer, should be as geospecific as possible.
    5. All warnings that originate from the NWS should retain the same name as the NWS has issued ( e.g., Tornado Warning should be called “Tornado Warning,” Flash Flood Warning should not be truncated to “Flood Warning,” etc.).
    6. Any wording added to the warning should be consistent with the original intent of the warning; new wording should not change the message.
    7. Any graphical depiction of the warning should be consistent with the original polygon.  For example, the best practice would be to color code only the portion of the county under the warning and not the entire county on a map. 


The above best practices have been established to ensure a robust delivery of weather warning information to the public.  Any questions concerning these best practices should be addressed to the Board of Best Practices at:

[email protected] 

[This statement is considered in force until January 2023 unless superseded by a new statement issued by the AMS Council before this date]