1. Hurricane Storm Surge Forecasting for Coastal Rivers David Welch, Senior Hydrologist Dave Ramirez, P.E., Senior Hydrologist National Weather Service Lower Mississippi River Forecast Center (LMRFC)

2. Acknowledgements University of Central Florida Coastal Hydroscience Analysis, Modeling & Predictive Simulations (CHAMPS) Laboratory University of Central Florida Coastal Hydroscience Analysis, Modeling & Predictive Simulations (CHAMPS) Laboratory USACE Vicksburg, New Orleans, Louisville, Mobile, Hydrologic Engineering Center USACE Vicksburg, New Orleans, Louisville, Mobile, Hydrologic Engineering Center USGS, Jackson, MS USGS, Jackson, MS FEMA, Region 4 FEMA, Region 4 Meteorological Development Laboratory (NWS) Meteorological Development Laboratory (NWS) Tropical Prediction Center (NWS) Tropical Prediction Center (NWS)

3. Overview of NWS River Forecast Center Operations Provide routine and flood stage forecasts for rivers and streams. Provide routine and flood stage forecasts for rivers and streams. Forecast for floods Forecast for floods Flash floodingFlash flooding Dam breakDam break Storm SurgeStorm Surge Forecasts from the RFC are transmitted to the public through the Weather Forecast Offices. Forecasts from the RFC are transmitted to the public through the Weather Forecast Offices. Approximate Workload 60% operations 40% development

4. Area of Responsibility ~220,000 mi 2 ~220,000 mi 2 479 Watersheds modeled 479 Watersheds modeled 223 Daily/flood only forecast 223 Daily/flood only forecast locations (5 day forecasts) locations (5 day forecasts) 16 28-day forecast locations 16 28-day forecast locations on Mississippi/Ohio Rivers on Mississippi/Ohio Rivers (issued weekly) (issued weekly) River/rainfall network of River/rainfall network of 2900 gages 2900 gages

5. LMRFC Hurricane Storm Surge Forecast Tools Real-Time: Real-Time: NWS Dynamic Wave Operational Model (DWOPER) and NWS Flood Wave (FLDWAV) Model coupled with Sea, Lake, and Overland Surge from Hurricanes (SLOSH) model output. NWS Dynamic Wave Operational Model (DWOPER) and NWS Flood Wave (FLDWAV) Model coupled with Sea, Lake, and Overland Surge from Hurricanes (SLOSH) model output. Scenario-Based: Scenario-Based: Surge Scenarios run with DWOPER for New Orleans SLOSH Basin. Surge Scenarios run with DWOPER for New Orleans SLOSH Basin.

6. Sea, Lake Overland Surge from Hurricanes (SLOSH) Model Run at the Tropical Prediction Center. Run at the Tropical Prediction Center. SLOSH output is a computed water surface elevation for each point on the modeled grid at each time step (34 basins modeled). SLOSH output is a computed water surface elevation for each point on the modeled grid at each time step (34 basins modeled). Normally obtain SLOSH model runs about 24 hours prior to hurricane landfall. Normally obtain SLOSH model runs about 24 hours prior to hurricane landfall. Runs are provided every 6 hours after initial run. Runs are provided every 6 hours after initial run.

7. New Orleans SLOSH Basin

8. DWOPER Lower Mississippi Surge Model Developed at the LMRFC in the early 1980s. Developed at the LMRFC in the early 1980s. Upstream boundary is discharge at Red River Landing, LA (RM 302.4). Upstream boundary is discharge at Red River Landing, LA (RM 302.4). Downstream boundary is stage at West Pointe a la Hache, LA (RM 48.7) or SLOSH elevation hydrograph. Downstream boundary is stage at West Pointe a la Hache, LA (RM 48.7) or SLOSH elevation hydrograph. Run on an hourly time step. Run on an hourly time step. Can be run with real-time SLOSH output or hypothetical storm surge scenario. Can be run with real-time SLOSH output or hypothetical storm surge scenario.

9. Storm Surge Scenarios TPC provided LMRFC 1,640 storm surge scenarios based upon a hurricane approaching New Orleans. Classified by: TPC provided LMRFC 1,640 storm surge scenarios based upon a hurricane approaching New Orleans. Classified by: Direction of storm track E, ENE, NE, NNE, N, NNW, NW, WNW, W.Direction of storm track E, ENE, NE, NNE, N, NNW, NW, WNW, W. Storm speeds of 5 or 15 mph.Storm speeds of 5 or 15 mph. Hurricane intensities from category 1 through 5.Hurricane intensities from category 1 through 5. Distance from New Orleans (160 miles left to 160 miles right of New Orleans).Distance from New Orleans (160 miles left to 160 miles right of New Orleans). LMRFC Lower Mississippi DWOPER surge model is currently set up to run 5 scenarios at one time. LMRFC Lower Mississippi DWOPER surge model is currently set up to run 5 scenarios at one time.

10. Tracks of NW Hypothetical Storms

11. Gustav Surge Scenarios

12. Hurricane Gustav SLOSH Run

13. Hurricane Gustav Real-Time Lower Mississippi Surge Forecast

14. Hurricane Ike SLOSH Run

15. Hurricane Ike Real-Time Lower Mississippi Surge Forecast

16. Hurricane Katrina SLOSH Run

17. Hurricane Katrina Real-Time Lower Mississippi Surge Forecast

18. Vermilion FLDWAV Model Stage Upstream Boundary Downstream Bound: VCPL1 NOS Tide blended with GFS Storm Surge. Inserted 5 miles below Perry (VRPL1). Lateral inflows derived from NWSRFS hydrologic model inserted into the Vermilion at: Lafayette Surrey St Hwy 733 Perry Geometry derived from HEC-RAS deck provided to LMRFC by USACE

19. Hurricane Ike Real-Time Vermilion Surge Forecast

20. UCF/LMRFC Collaborative Modeling on the Lower Pascagoula River, MS. UCF – 2-D River/Estuary/Ocean Model UCF – 2-D River/Estuary/Ocean Model Developed using ADCIRC grid of Gulf CoastDeveloped using ADCIRC grid of Gulf Coast Upstream flows from LMRFCUpstream flows from LMRFC LMRFC – Hydraulic River Model LMRFC – Hydraulic River Model Developed using upstream flow/stage hydrographs and downstream stage hydrographs for calibration.Developed using upstream flow/stage hydrographs and downstream stage hydrographs for calibration. Operational downstream stage hydrographs from UCFOperational downstream stage hydrographs from UCF Riverine bathymetry use by both LMRFC and UCF. Riverine bathymetry use by both LMRFC and UCF.

21. Pascagoula River Model Study Area Tributaries: Escatawpa River Red Creek Black Creek Big Creek Upstream boundaries: Black Ck @ Wiggins, MS. Pasc @ Merrill, MS. Agricola, MS. Big Ck @ Big Ck, MS. Red Ck @ Vestry, MS Local flows: Grahms Ferry, MS, Orange Grove, MS from NWSRFS Downstream boundary: SLOSH Model ADCIRC Model

22. Model Geometry Development

23. HEC-RAS Model Development

24. Future Work Conversion of LMRFC DWOPER and FLDWAV models to HEC-RAS. Conversion of LMRFC DWOPER and FLDWAV models to HEC-RAS. Complete development and calibration of Pascagoula model to ready for operational environment. Complete development and calibration of Pascagoula model to ready for operational environment. Development of new coastal hydraulic models. Development of new coastal hydraulic models. Inundation Mapping using GIS? Inundation Mapping using GIS?