1. Better Defining the Flood Threat Flood Inundation Mapping from the National Weather Service 2009 Severe Storms and Hydrology Conference Shreveport, LA Gregory P. Shelton NWS/West Gulf River Forecast Center

2. West Gulf River Forecast Center ADVANCED HYDROLOGIC PREDICTION SERVICE How can you get the river and rainfall information you need?

3. West Gulf River Forecast Center Advanced Hydrologic Prediction Service State of the science forecasting State of the science forecasting  Short and long term probabilistic forecasts  Water supply forecasts  Inundation mapping Innovation at all timescales Innovation at all timescales  Flash flood modeling  Distributed modeling  Ensemble modeling

4. West Gulf River Forecast Center Goals of AHPS Provide emergency and water resource managers information …   To make informed risk-based decisions   To optimize the use of resources Better meet the hydrologic needs of the country …   Plan with confidence and efficiency   Stay out of harms way   Provide valuable water supply information Enable the NWS to increase forecast skill and warning lead time

5. West Gulf River Forecast Center http://water.weather.gov Access to most NWS forecasts and data One internet address…

6. West Gulf River Forecast Center Rainfall - Past National Image is composed of Best Estimate QPE from the 12 CONUS RFCs Image can be downloaded in Shapefile or NetCDF format Various time spans are available from 24 hours to a year Durations beyond 1 day also have Normal, Departure from Normal, and Percent of Normal Click on map to zoom into states or select WFOs from list Toggles at bottom feature various geographic overlays

7. West Gulf River Forecast Center http://water.weather.gov Access to most NWS forecasts and data One internet address…

8. West Gulf River Forecast Center River Information

9. West Gulf River Forecast Center River Information

10. West Gulf River Forecast Center River Information

11. West Gulf River Forecast Center INUNDATION MAPPING Better Defining the River Flood Threat

12. West Gulf River Forecast Center Customer Input Familiarity with NWS flood severity categories Familiarity with NWS flood severity categories Utility of existing flood severity categories Utility of existing flood severity categories Retain existing flood severity categories Retain existing flood severity categories Enhance communication of flood risk by use of inundation graphics (maps) Enhance communication of flood risk by use of inundation graphics (maps)

13. West Gulf River Forecast Center Graphical Flood Impact Information Partnered with NC Floodplain Mapping Program Office, FEMA, and USGS to develop user-requested graphics to better convey flood threat Neuse River at Goldsboro, NC

14. West Gulf River Forecast Center Initial Steps Used partnered data (LIDAR Topo Engineering Data) from FEMA and NC Floodplain Mapping Program Used partnered data (LIDAR Topo Engineering Data) from FEMA and NC Floodplain Mapping Program Built unsteady hydraulic model for 73 miles of Tar River Built unsteady hydraulic model for 73 miles of Tar River Mapped flood forecasts in a GIS and presented results in easy to read format over the Web. (Text To Graphics) Mapped flood forecasts in a GIS and presented results in easy to read format over the Web. (Text To Graphics) Used operationally by SERFC as flood forecast tool during Hurricane Isabel – Sept. 2003 Used operationally by SERFC as flood forecast tool during Hurricane Isabel – Sept. 2003 Tar River Basin, NC Goal – To provide Web based flood inundation maps from the NWS operational forecast environment to emergency managers during flood events.

15. West Gulf River Forecast Center Static Libraries Predefined river stage levels and associated NAVD88 elevation. Yellow highlight indicates current level displayed. “Standard” and “Detailed” image options

16. West Gulf River Forecast Center Inundation Mapping Process Obtain and QC Base Data Obtain and QC Base Data  LIDAR, Topography, Aerial photography, Rating curves, Engineering data (preferably completed FIS)  Close collaboration with partners and customers  FEMA, River Authorities, USGS, Local EMs Develop Flood Profiles Develop Flood Profiles  Determine boundaries for hydraulic modeling of reach  Determine mapping intervals (1 ft, 2 ft, 4ft, etc.)  Develop flows that match rating curve stage for the mapping intervals  Export profiles to GIS for predetermined levels  Datum consistency!! Develop/Deploy Public Mapping Libraries Develop/Deploy Public Mapping Libraries  QA/QC by NWS staff  Flood depth grids and Inundation polygons delivered to contractor for development of web deliverables  Final product pushed to AHPS web pages

17. West Gulf River Forecast Center QA/QC Process Actual Location This is Harvard Street This is Heights Boulevard Move Gage Check GeoData Check GeoData  Lat/Lon at gage location  Stream centerline  Roads Check for non-contiguous inundation areas Check for non-contiguous inundation areas Check for correct reference data Check for correct reference data  Flood categories  Impacts statements  Historical crests Non-Contiguous Areas

18. West Gulf River Forecast Center Available Products Map types Map types  Predefined Levels  Flood Categories  Current Forecast Overlays Overlays  Street maps  Aerial photos Map Tools Map Tools  Zoom  Mouse over for water depth  Export to multiple formats (including shapefiles) Current forecast zoomed to forecast point Flood categories zoomed to nearby neighborhood Full map with aerial photo and predefined height displayed

19. West Gulf River Forecast Center Initial Inundation Mapping Locations

20. West Gulf River Forecast Center Inundation Mapping for Texas Most locations currently available Most locations currently available All available by end of 2009 All available by end of 2009 Partnerships with local governments and river authorities Partnerships with local governments and river authorities Additional locations also possible Additional locations also possible

21. West Gulf River Forecast Center Current Locations http://www.weather.gov/ahps/inundation.php

22. West Gulf River Forecast Center Example – Buffalo Bayou at Shepherd Drive Predefined river stage levels and associated NAVD88 elevation. Yellow highlight indicates current level displayed. “Standard” and “Detailed” image options Depth of water analysis available with Detailed Image

23. West Gulf River Forecast Center Example – Buffalo Bayou at Shepherd Drive Flood Categories available as overlays 100 & 500 Year Floodplains and Floodway Data available as overlays

24. West Gulf River Forecast Center Example – Buffalo Bayou at Piney Point Current Forecast: 60.3 FT at 18 UTC on 4/28/09 Current Forecast: 56.6 FT at 00 UTC on 4/29/09

25. West Gulf River Forecast Center Hurricane Ike Sequoia Estates: 56.3 59 S bound feeder: 55.2 N side channel: 54.9 Greens Bayou at U.S Hwy 59 – Crest 58.4 feet

26. West Gulf River Forecast Center IBWC Partnership Goal: Implement FIM on the Rio Grande Goal: Implement FIM on the Rio Grande  WMO Voluntary Cooperation Program  Seeking funding to cover implementation  Worked with IBWC to develop grant proposal  Utilize existing base data and modeling from IBWC  Approval delayed and project merged with larger bi-national negotiations  IBWC completed primary modeling work between Amistad and Falcon Reservoirs  Partnering to perform QC of polygons  Seeking new funding sources to cover implementation State of TexasState of Texas

27. West Gulf River Forecast Center Potential Mapping Locations El Paso Presidio Rio Grande City San BenitoBrownsville Del Rio Eagle Pass Laredo Columbia Bridge Mapping nearing completion Future potential mapping locations

28. West Gulf River Forecast Center Questions/Comments? Contact Info: Gregory P. Shelton, Service Coordination Hydrologist West Gulf River Forecast Center greg.shelton@noaa.gov (817) 831-3289 x219