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Extratropical Storm Surge Modeling

Presented By: Jesse Feyen (NOS/OCS, Storm Surge Roadmap)Contributors:

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Operational System Attribute(s)

System Name Acronym Areal Coverage Horz Res

Cycle Freq

Fcst Length

(hr)

Extratropical Storm Surge Operational Forecast System

ESTOFS Atlantic, Pacific

1-3 km

4x/dy 172

System Attributes

ESTOFS Hot start from previous simulation cycle using global tidal database (no D/A)

System Data Assimilation or Initialization Technique

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Why System(s) are Operational

Primary stakeholders and requirement drivers• NWS/Weather Forecast Offices, NWS/Ocean Prediction Center,

emergency managers, coastal managers, media• Need for surge+tide predictions for forecasting, coupling to NCEP/EMC

nearshore wave predictions What products are the models contributing to?

• NWS inundation forecasts in AWIPS, NWS surge prediction websites What product aspects are you trying to improve with your

development plans? • Cover Pacific Islands and Alaska, increase ensemble members, improve

resolution, couple to river hydraulic models for total water prediction Top 3 System Performance Strengths

• Advanced hydrodynamic model ADCIRC supports fully nonlinear physics, wave and river coupling, unstructured grids to resolve complex coastline

• Leverages extensive federal investments in model (USACE, FEMA)• Well validated for accurate water level predictions

Top 3 System Performance Challenges • Computational cost limits resolution, coverage of coastlines

• Limited ensemble members cannot address met uncertainties/scenarios• Not currently coupled to waves, rivers

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System Evolution Over the Next 5 Years

Major forcing factors• Part of Storm Surge Roadmap strategy to develop ensemble of coupled

total water prediction system to inform forecasters via coupling with wave, river hydraulic models

• Need to provide inundation guidance over all vulnerable coastlines (e.g., outlying Pacific Islands, Alaska)

Science and development priorities• Add additional forcing to increase ensemble members (now only GFS)• Develop, test, and transition coupling to wave and river hydraulic models

to provide total water predictions• Increase resolution to accurately predict local flooding (new Hurricane

Storm Surge Operational Forecast Sys. in dev. - down to 250 m)What are you top challenges to evolving the system(s) to meet

stakeholder requirements?• Insufficient computing resources for coupled ensemble high-res models• Insufficient model developers to sustain total water prediction R&D, O&M

Potential opportunities for simplification going forward• Coupled total water prediction connections between ADCIRIC and

hydraulic models• Continue coordination of inundation model dev. via Surge Roadmap

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Top 3 Things You Need From the UMAC

1. Clarity on importance, significance of total water prediction within NOAA modeling suite so that coupling and coverage can meet requirements

2. Support for computing resources for total water prediction (ensemble surge+tide+wave+river)

3. Recommendations on ensemble total water prediction coupled modeling strategy