1. Probabilistic Forecasts - Baseline Products for the Advanced Hydrologic Prediction Services (AHPS) Dave Reed HIC – LMRFC 2006 NWA Annual Meeting October 18, 2006

2. Today’s Talk Advanced Hydrologic Prediction Services Advanced Hydrologic Prediction Services Probabilistic Products from Hydrologic Ensembles Probabilistic Products from Hydrologic Ensembles Baseline Products Baseline Products Where to get products Where to get products AHPS National Status Map

3. AHPS Improved Science Improved Science –Better Hydrology –Distributed Modeling Utilize new and emerging technology Utilize new and emerging technology –Flood Inundation Mapping Probabilistic Forecasts up to 1 year in future Probabilistic Forecasts up to 1 year in future The Ohio River at Mounds, IL, Mar. 29, 1927 - river stage at Cairo, Illinois., 52.8 feet From: "The Floods of 1927 in the Mississippi Basin", Frankenfeld, H.C., 1927 Monthly Weather Review Supplement No. 29

4. Probabilistic Products Ensemble Streamflow Prediction System (ESP) Ensemble Streamflow Prediction System (ESP) Hydrologic Ensembles similar in function to meteorological ensembles Hydrologic Ensembles similar in function to meteorological ensembles Statistical Analysis done on ensembles Statistical Analysis done on ensembles Hannibal, MO – April, 1973

5. NCEP Ensemble Forecast

7. Hurricane Models – A Set of Ensembles

8. ESP Ensembles

9. Generates a series of ensembles based on current soil moisture conditions Generates a series of ensembles based on current soil moisture conditions Ensembles are hydrologic model runs using archived rainfall for 90-day period (8/31-11/29) for each year 1952-1997 Ensembles are hydrologic model runs using archived rainfall for 90-day period (8/31-11/29) for each year 1952-1997 Statistical analysis can be performed on ensemble members Statistical analysis can be performed on ensemble members

10. Example of Ensemble Statistics – Entire Run Period

11. Example of Ensemble Statistics – Selected Week Period

12. Potential Products Maximum, minimum, and mean Maximum, minimum, and mean Statistics for specified time periods - day, week, month Statistics for specified time periods - day, week, month Statistics for the entire period to compare to “normal” Statistics for the entire period to compare to “normal” Extremely flexible – user specified Extremely flexible – user specified

13. AHPS Baseline Products Weekly Statistics Statistical Analysis of Ensemble Members Statistical Analysis of Ensemble Members for each Week for each Week –Weekly Max Stage –Weekly Max Flow –Flow Volume Guidance on weekly Guidance on weekly –Likelihood of flooding –Minimum flows –Water supply volumes

14. AHPS Baseline Products Weekly Statistics

15. AHPS Baseline Products Entire Period Statistics Guidance on statistics during the Guidance on statistics during the entire run period entire run period –Maximum Stage –Maximum Flow Guidance on weekly Guidance on weekly –Possibility of flooding –Minimum flows/stages –Comparison to “normal”

16. AHPS Baseline Products Entire Period Statistics

17. AHPS Baseline Products Summary Weekly Products Weekly Products –Weekly Max Stage –Weekly Max Flow –Weekly Flow Volume Full Run Period Products Full Run Period Products –Maximum stage –Maximum Flow

18. Where to get the Info http://www.nws.noaa.gov/ahps/