Advanced Hydrologic Prediction Service AHPS…The Next Generation
Texas Floodplain Management Association 3 September 2015
David C. Schwertz, CFM Senior Service Hydrologist Houston/Galveston National Weather Service
Outline General Information Area of Responsibility Forecast Services NOAA Weather Radio Communications
Internet
HGX Web Presence
AHPS River Information Probabilistic Forecasts Inundation Mapping Rainfall Information Future Developments
NWS Houston/Galveston Area of Responsibility
23 County Warning Area
Offshore Waters out to 60 nm Includes Galveston and Matagorda Bays
Spotter Training 2000 1 Houston/Galveston Weather Forecast Office Operations
Watches and Warnings for Tornadoes…Severe Thunderstorms…Flash Floods
Marine Forecasts and Warnings
Local Forecasts out to 7 days
Heat Advisories
Fire Weather Forecasts
Aviation Forecasts for 8 Airports
Hydrology…River Flood Warnings and Statements
NWS Local Offices
13 River Forecast Centers (RFC) Precipitation Data River Forecasts Flash Flood Guidance Coordination with water managers (USACE, USGS, River Authorities)
125 Weather Forecast Offices (WFO) Local Weather Forecasts Local Warning and Watch Information Coordination with local emergency managers and first responders
RFC WFO
River Forecast Centers Weather Forecast Precipitation data & Forecasts Offices River forecasts issued to WFOs River forecasts ingested Public products/warnings issued
Precipitation estimates and Precipitation dataset forecasts merged into ingested into continuous dataset hydrologic model
Spotter Training 2000 2 WFO Houston/Galveston NWR Transmitter Sites NOAA Weather Radio provides a continuous broadcast of weather information and alarms when watches and warnings are broadcast.
Six NWS Transmitters in HGX CWA
College Station – 162.550 MHz
Lake Livingston – 162.500 MHz
Houston – 162.400 MHz
Galveston – 162.550 MHz
New Taiton – 162.450 MHz
Bay City – 162.425 MHz
Communication
Secure FTP Automatically ingests ALERT data
NWS Pager System Automatically disseminates warnings and other information
NWS Chat Allows internal two way communication between adjacent offices as well as emergency officials
Social Media
Facebook Facebook.com/nwshouston
Twitter Twitter.com/nwshouston
You Tube Youtube.com/nwshouston
Spotter Training 2000 3 WFO Houston/Galveston
ON THE INTERNET
Weather Information
www.weather.gov www.srh.noaa.gov/hgx
HGX Homepage
Spotter Training 2000 4 Watch Warning and Advisory Map
River flood polygons replaced county wide color coding.
Informational Graphics
Informational Graphics
Spotter Training 2000 5 AHPS Web Pages
INCLUDING RECENT UPDATES
River Information
River Information
www.waterweather.gov water.weather.gov/ahps2/index.php?wfo=hgx
Spotter Training 2000 6 Advanced Hydrologic Prediction Services
The AHPS Page provides detailed information for all the forecast points in our HSA.
AHPS National, Regional, and WFO HSA Maps now in an ESRI Interface
Users can employ ESRI’s full pan and zoom capabilities at the national, regional, and WFO HSA scales.
Clicking anywhere on the national map takes users to the appropriate WFO map.
Advanced Hydrologic Prediction Services
water.weather.gov/ahps2/index.php?wfo=hgx
Spotter Training 2000 7 HGX AHPS Page
User able to select among various base maps.
AHPS is also available on social media.
HGX AHPS Page
Users used to see a five character ID and river name when mousing over a site and had to click on the site to bring up its hydrograph.
Mousing over a site now displays the location’s associated hydrograph.
HGX AHPS Page
Spotter Training 2000 8 HGX AHPS Page – Map
Below the hydrograph is a map of the gage location, available in various base map formats.. Flood Categories, Historical Crests, Recent Crests, and Low Water information is also available.
HGX AHPS Page – Impacts
Below the map is a table of the associated Flood Impacts as well as Datum Information and Resource Links .
HGX AHPS Page – Map
FEMA Flood Hazard Layer available 2014
Spotter Training 2000 9 HGX AHPS Page
AHPS Hydrograph Page River at a Glance
Clicking on the River at a Glance tab allows you to select specific physical elements and build a profile of the entire river including tributaries and upstream points.
HGX AHPS Page AHPS Hydrograph Page Downloadable Information
Clicking on the Download tab allows you to download selected products for use in other applications. Selecting Probability Information displays the 90 day outlook for that point. Examples of probability graphs on next page.
AHPS Web Pages
PROBABILISTIC FORECASTS
Spotter Training 2000 10 AHPS Probability Information
Chance of Weekly Exceedance
AHPS Probability Information
Chance Exceeding During Period
Conditional vs Historical Simulation
A conditional simulation resets the model to the current model states when each water year interval is simulated…call it a rewind and reload process.
A historical simulation starts the model at current model states and runs nonstop through the entire input record. The model is allowed to become “wetter” or “drier” than current conditions prior to the run interval simulated.
Spotter Training 2000 11 Advantages of AHPS Probabilistic Products
Longer lead times for potential flooding
Provides range of potential flows
Provides information on relative risk to water managers and reservoir operators
These products can also be used for contingency forecasts Low/high flow scenarios Worst case scenarios using specific years of historical data (manual year weighting)
AHPS Web Pages
INUNDATION MAPPING
Inundation Mapping Available at Some Locations
Inundation mapping is available at some forecast points in Harris County and along the Colorado River.
Spotter Training 2000 12 Buffalo Bayou at Shepherd Drive
Use able to select among various base maps
Predefined river stage levels and associated NAVD88 elevation . Yellow highlight indicates current level displayed.
Buffalo Bayou at Shepherd Drive
Buffalo Bayou at Shepherd Drive
Spotter Training 2000 13 Buffalo Bayou at Shepherd Drive
AHPS Web Pages
RAINFALL INFORMATION
Advanced Hydrologic Prediction Services Rainfall Information
Spotter Training 2000 14 AHPS Precipitation
AHPS Past Precipitation
Zoom to Houston/Galveston Counties Overlay toggled on Specific Month Observed Precipitation Normal, Departure from Normal, and Percent of Normal values also available
May Rainfall
Spotter Training 2000 15 Recent Improvements
FUTURE ENHANCEMENTS
User Able to Quickly Identify Between
Data point
Forecast point
Forecast Point with Probabilities Color coded to categorical levels
Enabled users to view recent crests
Recent flood crests, even when not of historical magnitude (e.g., top 10), can be useful in communicating impacts from current or forecast flooding.
A list of recent crests now appears between historical crests and low water records.
Spotter Training 2000 16 Maximum forecast flood category download files now available for all time increments
Maximum forecast flood category shapefiles and KMZ files for all available time increments (1-day, 2-day, 3- day, 4-day, 5-day, 6-day, 7-day, 8-day, 9-day, and entire period) are now available by going to the WFO scale (Download Tab).
Previously only the maximum forecast flood category through day 2 files were available.
Users able to view normal pool elevations on the hydrograph
HPMs can now define the Normal Pool in AHPS.
Users easily able to identify sites with no flood stage and sites that are at or below their low water threshold Modifications to national and regional map legend.
Old National and WFO Map Legends New National and WFO Map Legends
Spotter Training 2000 17 Users able to select sites near or above flood stage or at or below low water thresholds using drop down menu
Experimental Long-Range Flood Risk
Experimental Long-Range Flood Risk
Information taken from Exceedance Probability Product
Spotter Training 2000 18 Ensemble Forecasts
Questions?
Contact Dave Schwertz NWS Houston/Galveston 1353 FM 646 W, Suite 202 Dickinson, TX 77539 281-337-5074 x228 [email protected] See our Web Page www.srh.noaa.gov/hgx
Spotter Training 2000 19