1. 1 Toward Modeling of River-Estuary-Ocean Interactions to Enhance Operational River Forecasting in the NOAA National Weather Service Hassan Mashriqui Seann Reed Cecile Aschwanden Office of Hydrologic Development (OHD) National Weather Service (NWS) 4 March, 2009

2. 2 Acknowledgement Jon Janowicz Federal Emergency Management Agency (FEMA), Region 3 Kevin Hlywiak Middle Atlantic River Forecast Center (MARFC), NWS

3. 3 3 122 Weather Forecast Offices (Outlined in Black) Current NOAA/NWS Hydrologic Service Delivery 13 River Forecast Centers (Colored)

4. 4 Current Forecast Hydrographs

5. 5 Coastal Areas Outside the Forecast Zones LMRFC SERFC MARFC

6. 6 Freshwater River-Estuary-Ocean (REO) Interactions Estuary Ocean Often we use numerical models to simulate these complex coastal environments

7. 7 Model Types 1D models – HEC-RAS/FLDWAV, SOBEK, MIKE 11 2D models – ADCIRC, MIKE 21, SELFE 3D models – CBOFS2, SELFE, DELFT3D, MIKE 3D

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9. 9 MARFC Daily Forecast Boundary Estuary Ocean Interactions River Tide & Wind River-Estuary-Ocean (REO) Interactions Modeling Freshwater

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11. 11 The Chesapeake Bay Operational Forecast System (CBOFS)  Operational forecast system by Center for Operational Oceanographic Products and Services (CO-OPS)/Coastal Survey Development Lab (CSDL) since August 2001  Nowcast and forecast Water Level  Nowcast and forecast Wind  Forecast for the ports within Baltimore Harbor and Hampton Roads.

12. 12 Little Falls near Washington, DC MARFC’s Forecast Point on the Potomac River Inflow boundary for the CBOFS is 7 miles from Little Falls forecast point

13. 13 Model Geometry is Important Error due to inaccurate boundary

14. 14 The Potomac River 1D HEC-RAS

15. 15 1936 Potomac River Flood

16. 16 1D HEC-RAS allows bridges to be coded in the model to determine the backwater effects. Many 2D/3D models do not have this capability

17. 17 HEC-RAS simulated water level profiles for the Potomac River near Washington DC Chain Bridge near DC

18. 18 Potomac River HEC-RAS domain

19. 19 Boundary Condition from CBOFS or SLOSH HEC-RAS will simulate water level near DC Hurricane Isabel, 2003

20. 20 HEC-RAS test simulation without freshwater inflow or wind forcing. Boundary tide at Lewisetta, Va and simulated water level near Washington DC September 2003 Stage (ft) Predicted water level near Washington DC Input water level near Lewisetta, Va

21. 21 Summary 1D – Fast, ready to use, accounts for bridges 2D/3D – Better physics, complex Application – depends on the customer need, project location etc.

22. 22 Thank you