Impact Based Warning Pilot Project

Beginning on April 2nd, the National Weather Service office in Topeka, KS will be taking part in a severe weather warning pilot project that will run through October 2012.

This is an Impact Based Warning pilot project that is not aimed at the general public. The target audience for this project is our Emergency Management and Media partners.

The goal of this project is

  • Improve communication of risk
  • Highlight potential impacts
  • Make important information easier to find within the warning message

The main changes to the warnings will be the addition of "tags" or short descriptors at the very end of a warning and is considered supplemental data (generally not seen by the public).  We will issue Severe thunderstorm warnings (SVR) as we have in the past and continue to add hail and wind tags at the very bottom of the warning as we have in the past.  However, if we are anticipating the hail size to be 2.75 inches (baseball size) or larger and/or the winds to be 80 mph or greater, the follow up statement will include within the body of the warning "This is a very dangerous storm".  These selections will not require a new warning to be issued.

In rare cases, a particular storm may have a small potential for a tornado (landspout, squall line tornado)  and the forecasters confidence is too low to issue a tornado warning.  Therefore, within the initial severe t-storm warning or followup severe weather statement a "Tornado...possible" tag may be appended within the supplemental data at the very bottom of the warning.   This allows those in decision making positions an opportunity to follow that particular storm a bit closer and monitor for a potential upgrade to a tornado warning. This tag will not occur with every SVR warning issued within a tornado watch.

As for tornado warnings, they will continue to be issued as they have in the past.  However, if by using our scientific expertise in analyzing environmental conditions, interrogating radar data, and listening to spotters observing the storm we feel a greater threat for significant damage is possible or is occurring, we will add a tag (Tornado damage threat...significant) at the bottom of the warning to better convey risk, potential impacts and do so in a format that allows the most important information to be found quickly within the warning message.  Once again, this will not require a new warning be issued. Instead, this information will be appended to the bottom of a follow up severe weather statement or at the bottom of the warning.

In exceedingly rare cases the tag (Tornado damage threat...catastrophic) may be utilized when a confirmed tornado poses a severe threat to human life and catastrophic damage from a tornado is imminent or ongoing.  The NWS does have the option to issue a new warning if this is expected  as it may be in everyone's best interest to be alerted again for such a catastrophic event.  Within the body of the warning, the phrase "A tornado emergency for abc city" will be added into the warning text.  Once again, the use of this tag would be exceedingly rare and would only be used when reliable sources confirm a tornado or there is clear radar evidence of the existence of a damaging tornado such as the observation of a debris/damage signature.

Lastly, the NWS is working very closely with social scientists throughout this entire project.   They along with our partners (media, emergency managers, and private vendors) will provide input throughout the project to help evaluate the effectiveness of the changes.

For a video summarizing this project please click on the following link.

Impact Based Warning Pilot Project


If you have any additional questions regarding this test project contact:

Chad Omitt

Warning Coordination Meteorologist

National Weather Service Topeka, Kansas

Return to News Archive is the U.S. government's official web portal to all federal, state and local government web resources and services.