POLYGON WEATHER WARNINGS – A NEW APPROACH FOR THE NATIONAL WEATHER SERVICE

1. POLYGON WEATHER WARNINGS – A NEW APPROACH FOR THE NATIONAL WEATHER SERVICE Ken Waters National Weather Service, Honolulu HI May 17, 2005 Public Service Meeting – Park City, UT

2. 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 • 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 Ken Waters, NWS Pacific Region

3. WARNGEN • 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 Ken Waters, NWS Pacific Region

4. Using GIS with Polygon Warnings • Polygon vertices well-suited to include in GIS • Mechanism was established to strip off the lat-long polygon information, database the polygons, and create real-time GIS shapefiles • Using only open source (“freeware”) software • Code written in Perl • Polygon values formatted in ESRI “gen” format • Use “gen2shp” and “txt2dbf” packages Ken Waters, NWS Pacific Region

5. County vs. Polygon • Latitude/Longitude points at the bottom of all TORs, SVRs, FFWs, and SMWs. Ken Waters, NWS Pacific Region

6. Polygon Advantages • Shows specifically where the threat is • 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 Ken Waters, NWS Pacific Region

7. Polygon Advantages Polygon Eliminates Area False Alarmed Ken Waters, NWS Pacific Region

8. NWS Identifies a Need • Feb. 2004: Regions meet to study this issue • Mar. 2004: Meeting Information presented to MSD Chiefs • Apr. 2004: Gen. Johnson asks PR Regional Director Jeff LaDouce to commission a polygon warning team • June 2004: Meeting information presented to Ops Committee • June 2004: Polygon Team Chartered • Aug. 2004: First formal Polygon Team Meeting • Sept. 2004: Verification Scoring Sub-team Launched • Jan. 2005: AMS Presentation • Mar. 2005: Prototype Test Started Ken Waters, NWS Pacific Region

9. Team Members • Mike Looney, CRH (facilitator) • Mike Coyne, SRH • Steve Naglic, WCM WFO Columbia SC (ER) • Pete Wolf, SOO WFO Wichita, KS (CR) • Jeff Lorens, WRH • Brent McAloney (OCWWS) • Rich Okulski (OCWWS) • Noreen Schwein, CRH (Hydrology) • Joe Shaffer, SPC • Ken Waters, PRH Ken Waters, NWS Pacific Region

10. Prototype Test Ken Waters, NWS Pacific Region

11. Jackson MS Apr 5-7“Trial by fire” Ken Waters, NWS Pacific Region

12. And now, some examples, using 2004 warnings Ken Waters, NWS Pacific Region

13. Tornado Warnings -- 2004 Ken Waters, NWS Pacific Region

14. Tornado WarningsFlorida 2004 Ken Waters, NWS Pacific Region

15. Severe Thunderstorm Warnings Ken Waters, NWS Pacific Region

16. Severe Thunderstorm Warnings Ken Waters, NWS Pacific Region

17. Tendency to align warnings to county borders continued in 2004 Ken Waters, NWS Pacific Region

18. Flash Flood Warnings Ken Waters, NWS Pacific Region

19. Special Marine Warnings Ken Waters, NWS Pacific Region

20. Flash Flood Warningsstill very “county-based” Ken Waters, NWS Pacific Region

21. Applications For Viewing Polygon Warnings • CONUS map showing warnings, updated each minute: http://www.prh.noaa.gov/regsci/gis/ • ArcIMS map service for historical viewing: http://www.prh.noaa.gov/regsci/gis/ • Texas A&M Site (warnings + radar): http://www.prh.noaa.gov/regsci/gis/warn.html • Iowa Mesonet: http://mesonet.agron.iastate.edu/GIS/apps/rview/warnings.phtml Ken Waters, NWS Pacific Region

22. Display of warnings onlyhttp://www.prh.noaa.gov/regsci/gis/ Ken Waters, NWS Pacific Region

23. Busy Day….! Ken Waters, NWS Pacific Region

24. ArcIMS Map Servicehttp://www.prh.noaa.gov/regsci/gis/warn.html Ken Waters, NWS Pacific Region

25. Includes LSR data from SPC Ken Waters, NWS Pacific Region

26. Texas A&M Mesonet Sitehttp://mesonet.tamu.edu/PolygonTest/ Ken Waters, NWS Pacific Region

27. Iowa Environmental Mesonethttp://mesonet.agron.iastate.edu/GIS/apps/rview/warnings.phtml Ken Waters, NWS Pacific Region

28. The Challenges • Internal to NWS • Forecaster paradigm shift to focus on weather threat • Workload issues keeping track of warnings • Ensuring events don’t slip between nearly adjacent warnings • Verification measures • Changes to GPRA baselines • Special verification issues (e.g., multiple warnings for same county) • Software • WARNGEN error -- periodically issues 2-point polygons well out of CWA • External to NWS • Dissemination! • Many TV Stations not prepared to display polygons • Niche market for private sector (e.g., WeatherData) • NOAA All-Hazards Radio • Technical limitation: location is based only on county • New generation of NWR needs to allow users to input either lat/long or nearest city to take advantage of polygon technology Ken Waters, NWS Pacific Region

29. Questions? • Updated every minute for TOR, SVR, FFW, SMW, as well as SPC watches • Available at: • http://www.srh.noaa.gov/hq/regsci/gis Ken Waters Regional Scientist NWS Pacific Region Honolulu, Hawaii Ken.waters@noaa.gov (808) 532-6413 Ken Waters, NWS Pacific Region