# Presentation: 606969

## Storm-based Warnings

- NWS Partner’s Meeting
- January 18, 2007
- John Ferree
- NOAA’s National Weather Service

**Notes:**
Hi! My name is John Ferree and this short 12 minute presentation is on an exciting change to the National Weather Service’s warning program...Moving from warnings issued on a county-wide basis to storm-based warnings. 

## From County-Based Warnings to Storm-Based Warnings

- County-Based Tornado Warnings
- 8 Counties under warning
- Almost 1 million people warned

- Storm-Based Tornado Warnings
**70% less** area covered
**~600,000 fewer** people warned

-  More specific
-  Increased clarity
-  Supports newdissemination technology

**From County-Based Warnings**** to Storm-Based Warnings**

- Three simultaneous tornadoes within line of severe thunderstorms

**Notes:**
Here is an example to illustrate some of the benefits of going from county-based warning to storm-based warnings. In this case, there were actually three significant tornadoes on the ground at the same time. Eight counties were included in tornado warnings, with almost a million people under a tornado warning. With storm-based tornado warnings only those area that are threatened are in the warning, not the entire county. In this case, 70 percent less area was covered by warnings, and approximately 600,000 fewer people would encouraged to take immediate cover. A test of storm-based warnings in 2005, actually showed that warning area could be reduced by around 70 percent. There are several other benefits to going to storm-based warnings including being able to increase specificity and clarity with the warning. The more geographically based warnings also are supported by new dissemination technologies.  

## Effective Storm-Based Warnings Can Avoid Unnecessary Warning  of Population Centers

**Most of the Dallas/Fort Worth metropolitan area is correctly omitted from this Storm-Based tornado warning. New siren system selectively activated.**

***“******Storm-based warnings would save the public a minimum of $100 million dollars a year in reduction of the cost of sheltering”***
- - Dr. Dan Sutter   Professor of Economics

**Notes:**
In this case, a fast moving tornadic storm was expected to move rapidly across northern portions of Tarrant and Dallas Counties. Most of the Dallas/Fort Worth metropolitan area is not threatened by this storm. With storm-based warnings, new siren systems can be selectively activated for just those communities that are directly threatened. A study done by Dr. Dan Sutter a professor of Economics at the University of Oklahoma and now the University of Texas Pan-Am found that storm-based warnings would save the public a minimum of $100 million dollars a year in reduction of the cost of sheltering. 

## An Extreme Example ofFalsely Alarmed Area

**Severe Thunderstorm Warning for San Bernardino and Riverside Counties CA**** **
**Warning area = State of IL**** **
**Actual area threatened = Small county in IL**

**Notes:**
The problem of warning entire counties is especially problematic in the western U.S. where counties are larger. San Bernardino county is the largest county in the U.S. and is 13 times larger than the state of Rhode Island. This warning also included Riverside County. The area is outline in yellow, and the two counties cover nearly 60,000 Square Miles – larger than the state of Illinois. The storm was not moving very fast and the area of threat was actually very small. The storm-based warning would cover less than 300 square miles, about the size of a small county in IL. 

## Graphic Disseminationof Storm-Based Warnings

**Notes:**
A recent NSF study shows that a majority of Americans obtain weather information that includes graphic capabilities such as television, the Internet, PDAs, cell phones, etc.
Partners including Brian Busby at the ABC affiliate in Kansas City, MO are beginning to take advantage of these graphic capabilities. His vendor provides the storm-based warnings.  What you see is a screen capture not a pose.  WFO EAX issued a SVR (blue) then upgraded to a TOR (red).  This episode was the first time Brian displayed the polygons.

## Digital Emergency Alert System (DEAS) Will Improve Direct Dissemination 

- Any digital device
- Digital TV
- Satellite Radio
- Internet
- Cell Phone
- PDA
- Geo-located
- Text, Audio, Video

**Notes:**
The previous slide showed how our SB warnings can now be displayed on a number of devices.
A recent NSF study shows a majority of Americans now obtain weather information via the internet, TV, and handheld devices.
More difficult is how to describe a SB warning via text or voice.
DEAS is on the horizon and will go a long way towards solving this problem.   DEAS-accessible devices will activate immediately if the device is within the geo-targeted area.    Of course, that could include devices which are in moving vehicles with enter SB warned areas.
For now, EAS still warns entire counties including NWR

## Challenges for SB WarningsCounty Warning Area Boundaries

**St. Louis CWA**

**Paducah CWA**

**Lincoln CWA**

**Notes:**
There are challenges for storm-based warnings that still need to be worked out. In the example the tornadic storm is in Randolph County, IL with is in the St. Louis NWS office forecast and warning area. The storm will be moving NE and impact both portions of Perry County, IL that is in Paducah’s County Warning Area (CWA). In this example, ,having multiple warnings for Randolph, Washington, and Perry county is not ideal. It would be better if the one office could issue a storm-based warning for the entire area. To do this will take extensive operational testing to make sure there is adequate collaboration between offices, and that all dissemination systems are prepared to handle this issue.  

## Challenges for SB WarningsCounty Warning Area Boundaries

- Madison

- Bond

- Clinton

- Fayette

- Marion

- St. Clair

- Washington

- Randolph

- Perry

- Jackson

- Franklin

- Jefferson

- Hamilton

- Williamson

- Saline

- Wayne

- Clay

**St. Louis CWA**

**Paducah CWA**

**Lincoln CWA**

**Issued by STL**

**STL**

**PAH**

**ILX**

**Notes:**
When it comes time to reissue this warning, perhaps a different office (in this case Paducah) will issue the warning even though part of the warning is for southeastern Washington count in St. Louis’s area.  
Again, this is just a prototype, and we plan to test various cases prior to testing the process on a limited basis in real-time. Only when all process, collaboration, and dissemination issues both within the NWS and externally with our partner’s and customers implemented nationwide.   

## Multiple Warnings in One County/Parish

- Issue for text, radio, TV crawls
- Add reference to other valid warnings
- Include counties with directional delimiters?
- Summary severe weather statements?

- Madison

- Bond

- Clinton

- Fayette

- Marion

- St. Clair

- Washington

- Randolph

- Perry

- Jackson

- Franklin

- Jefferson

- Williamson

**TOR until 3:30PM**

**SVR until 3:45PM**

**Notes:**
The last challenge for storm-based warnings that I will mention in this presentation also relates to the listening audience or text only users. When there are multiple warnings over the same county, there is a potential for confusion. In the example, when a listener in Washington county hears that the tornado warning has expired at 3:30PM they will also need to know that the severe thunderstorm warning continues until 3:45PM. This may require a list of other valid warnings appended to each warning at issuance. Another consideration yet to be determined is if there will be summary severe weather statements when multiple warnings are in effect? These are all ideas that will be tested first in simulations, and then in limited real-time situations in consultation with the private sector prior to nationwide deployment.  

## Challenges for SB WarningsText /Audio Dissemination 

- Already use directional delimiters
*“**Tornado Warning for *_***Southern***_* Ford County”*
- Additional cities, towns, landmarks, highway mile markers

**Notes:**
Another challenge for Storm-based warnings is how best to convey the area covered by a warning verbally over the radio or in text where graphics are not available. The NWS has already begun use of directional delimiters with some counties. The “locations impacted” list will also be expanded especially in rural areas to include more small communities, landmarks, highway exit or mile markers, etc. 

There will be some people warned over the radio (including NWR) that are not in the storm-based warning. Although, the benefits of storm-based warnings are not as great for those without access to graphical depictions or some geographical information systems (GIS), there is not a degradation of the current service.  

## Minor Enhancement Planned to Warning Format 

- Add location and motion of feature
- Estimated location of tornado, leading edge of gust front, leading edge of hail core, or other.

**Notes:**
The only major change prior to the implementation is the addition of the feature location and movement in coded format below the latitude and longitude of the polygon vertices. Other enhancements are likely and we will rely on input from the Weather Enterprise for guidance. 

## Short-term Warning Formats Discussed at SB Warning Workshop

- Format warnings in a more machine readable format such as CAP (Common Alerting Protocol) or XML  (Extensible Markup Language)
- Example from Melissa Tuttle-Carr at The Weather Channel

**Notes:**
The workshop began a dialog to make warnings more machine readable so they can be rapidly transmitted over a variety of digital devices.

## Slide 13

**Notes:**
A mock-up example of an enhanced CAP formatted warning from Melissa Tuttle Carr at the Weather Channel.

## Here’s the Plan

- Begin storm-based warnings (TOR, SVR) on October 1, 2007
- Currently gathering feedback from partners and customers
- Broadcasters (NWA, AMS, E-mail lists)
- Emergency managers (IAEM, NEMA, E-mail lists)
- Private Sector Meteorologist
- December 5-6 – Technical Dissemination Workshop at Texas A&M in College Station, Texas
- Developing software and training to support forecasters

**Notes:**
The plan is to initially replace county based warnings with storm-based warnings on October 1, 2007. Although, the official announcement of that change will not occur until the AMS meeting in San Antonio in January 2007. We continue to gather feedback from partners and customers, and will continue to gather feedback well beyond initial deployment.  This planned change will not work unless it works for the private sector vendors of NWS warnings, emergency managers, and the media.   

## Questions?

- Contact Information:
- John.T.Ferree@noaa.govPhone 405-325-2209

**Notes:**
Thanks you for listening. We will have a frequently asked question page on this web site very soon.  Please feel free to contact me with any questions on Storm-Based Warnings.