Flood Inundation Mapping Coming to the NWS Birmingham AL AHPS Page
The National Weather Service (NWS) is enhancing the communication of flood risk and impacts through the use of Advanced Hydrologic Prediction Service (AHPS) flood inundation maps. This ongoing project has been developed in partnership with other government agencies. The final inundation maps and web interface will be the result of extensive outreach, including responses to numerous surveys and direct interaction with partners and customers at several local, regional, and national venues.
Flood Inundation Maps show the extent of flooding expected spatially over a given area. This will indicate where roadways, streets, buildings, airports, etc., are likely to be impacted by floodwaters. An easily accessible map graphics will provide users more awareness of the flood hazards in their local community. Combined with river observations and NWS river forecasts, inundation maps will provide decision-makers additional information needed to better mitigate the impacts of flooding and build more resilient communities.
A library, or collection of inundation map graphics, is created for each river forecast location. The AHPS webpage also includes a text version of the actual river forecast as well as a graphical forecast hydrograph. Impact and historical information is also included with the inundation maps. User-selectable displays will provide maps for various inundation levels or flood categories. The interface will also include an interactive mouse locator water depth feature.
The interface will provide the ability to view inundation levels at stages in the minor, moderate, and major flood categories. The 100-year flood, 500-year flood, and the floodway zones may also be displayed. From this interface, the user can also view maps of observed or forecast inundation levels based on current NWS river forecasts. The user has the option to use either a standard map background showing basic features such as
main roads and highways or a detailed background based on areal photography.
Currently, only a limited number of NWS forecast locations have a flood inundation mapping interface.  The first inundation maps for Central Alabama will be for the Black Warrior River at the Oliver Lock and Dam in Tuscaloosa. These maps are nearing completion and should be on the National Weather Service, Birmingham AHPS page on or before September 30th. 
Locations elsewhere in the country that are currently available can be found  at the following URL:

Below are some examples of flood inundation maps that can be viewed on the AHPS web sites.

                       Flood Inundation Map for Specific Stage Value


                      Flood Inundation Map Displayed on Aerial Image


                     Inundation Image for Major Flood Category


                    Inundation Image for 100 Year Flood


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