1 / 19

Polygon Warnings

Polygon Warnings . Mike Coyne National Weather Service Southern Region. Overview. Background Information The advantages of polygon warnings What are the issues concerning the polygon? What is currently being done Future Plans. Background.

Antony
Download Presentation

Polygon Warnings

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Polygon Warnings Mike Coyne National Weather Service Southern Region

  2. Overview • Background Information • The advantages of polygon warnings • What are the issues concerning the polygon? • What is currently being done • Future Plans

  3. Background • National Weather Service issues four types of short-fused warnings: • Tornado Warnings (TOR) • Severe Thunderstorm Warnings (SVR) • Flash Flood Warnings (FFW) • Special Marine Warnings (SMW) • Issued normally for one county at a time • Can lead to a large false-alarm area, especially in the case of large or irregular-sized counties

  4. Background • Verification has been strictly county-based • Legacy dissemination methods all tied to counties: • NOAA All-Hazards/Weather Radio • Uses SAME alert code based on counties • Internet displays – again, based on counties

  5. What is the Polygon?

  6. What is the Polygon? • Allows forecaster to graphically highlight the area of greatest threat • Creates a template text product for the warning, including proper headers, issue/expiration times, county UGC codes • ALSO: includes latitude/longitude vertex points for the pathcast, or polygon warning --- LITTLE USED by NWS, partners, and public

  7. What is the Polygon?

  8. Polygon Advantages • Shows specifically where the threat is located • More accurately shows warning area on systems displaying warnings graphically • Reduction of risk area to public • Better graphical description capabilities • Wider local distribution via cell phones, PDAs, etc. • Increase NWS role in the confirmation part of the warning process • Private sector starting to turn to polygons • Allows NWS to refine warnings to true threat area • Allows us to track and set goals for false alarm area • Better warning quality • Keeps NWS in technological step

  9. Polygon Advantages Polygon Eliminates Area False Alarmed

  10. One WFOs Study (2004) • In 2004, issued tornado warnings that covered: • 31,990 square miles (494 individual towns) • Utilizing the polygon approach, the polygons covered: • 9,500 square miles (152 individual towns) • If the polygon approach were in place: • Would have reduced our total warning area by 22,490 square miles • Would have unnecessarily warned 242 fewer towns • That's a reduction of 70%!

  11. Better Warning Information

  12. Better Warning Information

  13. Better Warning Information

  14. Polygon Issues • How should NWS treat these warnings? • Is the polygon the area of maximum threat? • Is the polygon the warning area? • What does our customers/partners wish to see? • What are the internal and external education issues with polygon warnings? • Do we need to reexamine the entire warning process?

  15. Other Issues • Training: • Software (e.g. Warngen, WWA, Storm Data) • How to train at the operation interface (scientific, technical, cultural) • Dissemination: • Education/public outreach • Interoperability of dissemination systems • How to handle cross-CWA boundary issues (polygons crossing from one CWA to another)? • Customer concerns over potential increase in number of warnings (broadcast interruptions, etc.) • Verification: • How to measure skill w/respect to polygon warnings? • Consider and understand potential impact on GPRA goals • Operations: • Workload (keeping track of multiple polygons; multiple small polygons, or few large polygons? – situation dependent?) • Do we restrict to short-fuse warnings or extend to long-fused warnings

  16. No Issue is Trivial 2 maps of all Polygon Warnings Issued in 2003 Can you see the counties?

  17. Polygon Team • NWS Polygon Team formed in 2004 • Purpose: Define issues associated with the polygon approach to the warning process and recommend solutions. • Test will be run in 2005 with some NWS forecast offices • De-emphasis on county borders • Focus on location of severe threat • Test alternate measures of verification that are polygon-based • Will open the door for dissemination using current technologies (e.g., cell phones, pagers, GPS-enabled devices)

  18. Team Members • Mike Looney, CRH (facilitator) • Mike Coyne, SRH • Steve Naglic, WCM WFO Columbia SC (ER) • Pete Wolf, SOO WFO Jacksonville, FL • Jeff Lorens, WRH • Ken Waters, PRH • Brent MacAloney (OCWWS) • Rich Okulski (OCWWS) • Noreen Schwein, CRH (Hydrology) • Joe Schaefer, SPC

  19. Questions Mike.Coyne@noaa.gov (817) 978-1100 x. 153

More Related