1. UMAC data callpage 1 of 16Nearshore Wave Prediction System (NWPS) EMC Operational Models Nearshore Wave Prediction System (NWPS) André van der Westhuysen Support Scientist III, IMSG at Environmental Modeling Center NOAA / NWS / NCEP Andre.VanderWesthuysen@NOAA.gov

2. UMAC data callpage 2 of 16Nearshore Wave Prediction System (NWPS) Content Description of the current modeling system. Existing model verification statistics documentation and associated web sites. Future plans for the next 5 years. Sources and selection of requirements and development path. Nearshore Wave Prediction System (NWPS)

3. UMAC data callpage 3 of 16Nearshore Wave Prediction System (NWPS) Current operational configuration of NWPS (new implementation 2015) NWPS is a downscaled, coastal wave modeling system for providing wave forecast guidance to coastal Weather Forecast Offices (WFOs) that are consistent with their marine wind forecasts. Currently implemented in NWS Southern and Eastern Regions, and the National Hurricane Center (Tropical Analysis and Forecast Branch). NWPS is an on-demand modeling system, forced by forecast wind fields submitted by WFOs via a baselined GUI in AWIPS. Additional forcings from other NCEP models include: wave boundary conditions from WAVEWATCH III, water levels from ESTOFS (extra-tropical) and P- Surge (tropical), and surface currents from RTOFS Global. The system provides 102-hr forecast guidance for two cycles a day (on average). Basic forecast products include integral parameters of wave fields, partitioned and tracked wave systems, wave spectra, and statistical wave runup and rip current guidance (currently at pilot sites only).

4. UMAC data callpage 4 of 16Nearshore Wave Prediction System (NWPS) NWPS Configuration ComponentDetails Wave Model Dynamics and grid configuration Community model SWAN v40.81 Geographic coordinates (lat/lon) Dedicated computational grid for each coastal WFO, covering their County Warning Area (CWA). At present, this is a regular grid (CG1), with up to four nested grids (CG2-CG5) covering regions of specific interest. Overall CG1 grid at 1.8 km resolution, nested grid typically 500 m, but higher (e.g. 50 m) as required by individual WFOs (e.g. to drive rip current guidance). Regional-scale application (12 km) in the tropical Atlantic and Pacific basins, to provide NHC/TAFB with wave guidance consistent hurricane wind forecast. Wave Model Physics Deep water source terms (SWAN default): Komen et al. (1984), as recalibrated by Rogers et al. (2003). Shallow water source terms (SWAN default): JONSWAP bed friction, Battjes and Janssen (1978) depth-induced breaking, LTA triads. Wave system tracking from WW3 v4.18 Statistical wave runup guidance (Stockdon et al. 2006). Statistical rip current guidance (Dusek and Seim, 2013). Model forcings and Data Assimilation Wind forcing from real-time, forecaster-developed wind fields from AWIPS/GFE (pre-NDFD). Forecaster winds based on models such as GFS/NAM/WRF, but enhanced manually in GFE using observations or forecaster expert judgement.

5. UMAC data callpage 5 of 16Nearshore Wave Prediction System (NWPS) NWPS Configuration ComponentDetails Model forcings and Data Assimilation (continued) Wave boundary conditions taken from NCEP’s operational WAVEWATCH III. Surface current forcing taken from NCEP’s HYCOM-based RTOFS Global. Water levels taken from NOAA/NOS’s ADCIRC-based ESTOFS (extra-tropical conditions) and SLOSH-based probabilistic P-Surge (tropical conditions). Post- Processing and products Field output of integral wave parameters in GRIB2 format. Field output of partitioned and tracked wave systems in GRIB2 format. Web graphics of integral wave parameters, wave spectra and wave system time series, hosted on polar.ncep.noaa.gov/waves/nwps/. Time series output of wave runup and rip current probability (ASCII text), at four pilot sites in 2015 implementation. Workflow and Scripting Scripting written in Perl, Python and Bash, and automation based on NOAA EC-Flow workflow manager. WFO model GUI and run triggering written in Python, and baselined in AWIPS II v14.1.1.

6. UMAC data callpage 6 of 16Nearshore Wave Prediction System (NWPS) NWPS domains FY15 Southern Region WFOs Eastern Region WFOs (Nested subdomains shown in red)

7. UMAC data callpage 7 of 16Nearshore Wave Prediction System (NWPS) NWPS GUI in AWIPS 14.4.1

8. UMAC data callpage 8 of 16Nearshore Wave Prediction System (NWPS) Example output WFO New Orleans WFO LIX, CG1 (1.8 km) CG2 (500 m)

9. UMAC data callpage 9 of 16Nearshore Wave Prediction System (NWPS) NWPS Documentation Scientific documentation: –Van der Westhuysen, A. J., R. Padilla-Hernandez, P. Santos, A. Gibbs, D. Gaer, T. Nicolini, S. Tjaden, E. M. Devaliere and H. L. Tolman. Development and validation of the Nearshore Wave Prediction System. Proc. 93 rd AMS Annual Meeting, Am. Meteor. Soc., Austin, 2013 [PDF].PDF Documentation of Operational Scripts and Implementation Details: –http://polar.ncep.noaa.gov/waves/nwps/http://polar.ncep.noaa.gov/waves/nwps/ Display of Real-time Products: –http://polar.ncep.noaa.gov/waves/nwps/http://polar.ncep.noaa.gov/waves/nwps/

10. UMAC data callpage 10 of 16Nearshore Wave Prediction System (NWPS) NWPS Performance Initial results using default SWAN physics show good performance of this new implementation Refer to NCEP CCB Briefing on 2015 NWPS implementation for model performance statistics: http://polar.ncep.noaa.gov/waves/nwps/http://polar.ncep.noaa.gov/waves/nwps/ NWPS/SWAN: H sig Comparison to NBDC buoys over Southern Region WFOs: 2014/10/11-2015/05/20

11. UMAC data callpage 11 of 16Nearshore Wave Prediction System (NWPS) Future Plans Expansion of centralized NWPS to Western, Alaska and Pacific Region WFOs (12). Milestone for FY16. Implementation of on- demand NWPS for Ocean Prediction Center (N. Atlantic extra-tropical latitudes). Milestone for FY16.

12. UMAC data callpage 12 of 16Nearshore Wave Prediction System (NWPS) Future Plans Replace regular grids and nesting with unstructured meshes, designed in collaboration with WFOs to highlight regions of local interest (e.g. inlets, ports, popular/beaches). Increased nearshore resolution (200-500 m) to improve accuracy for nearshore applications (next slide).

13. UMAC data callpage 13 of 16Nearshore Wave Prediction System (NWPS) Future Plans Nationwide expansion of statistical wave runup and rip current guidance. Addresses Sandy Service Assessment recommendation regarding wave runup (Sullivan & Uccellini 2013). Milestone for FY17. Partnership with NOAA/NOS and USGS.

14. UMAC data callpage 14 of 16Nearshore Wave Prediction System (NWPS) Future Plans Downscaled, coupled wave and surge modeling using ADCIRC- SWAN model (Dietrich et al. 2010). Incorporates interactions between waves and storm surge (e.g. radiation stresses, wave-current interaction). Coupled NWPS system forced by GFE forecaster wind fields. Water level boundary conditions (tide and surge) taken from ADCIRC-based regional-scale ESTOFS model. Prototyped during Sandy Supplemental (2013-2015). Operational milestone for FY19/20.

15. UMAC data callpage 15 of 16Nearshore Wave Prediction System (NWPS) ComponentsQ3FY15Q3FY20 Wave model physicsRogers et al. (2003) (SWAN default).Model validated for state-of-the-art physics package, e.g. Ardhuin et al. (2010), or improvement. BasinsImplemented for NWS Southern and Eastern regions, NHC/TABF Atlantic and Pacific domains. Implemented for all coastal WFOs nationwide, NHC/TAFB (tropical) and OPC (extra-tropical). Model meshesCG1 domain at 1.8 km, with nesting down to 500 m (CG2-CG5). Unstructured meshes, with variable resolution from 1.8 km offshore to 200-500 m in the nearshore. Model couplingUncoupled system, uses water levels as inputs only. Coupled system (depth-integrated), using ADCIRC-SWAN model. Wave runup and rip current guidance Available at four pilot sites along the East Coast. Guidance extended nationwide. Estimated compute factor 4 nodes continuously reserved on WCOSS Phase II. 16 nodes continuously reserved on WCOSS Phase II. Future Plans (Summary)

16. UMAC data callpage 16 of 16Nearshore Wave Prediction System (NWPS) Sources and selection of requirements and development path NOAA Storm Surge Roadmap provides high-level national vision and coordination (www.stormsurge.noaa.gov). Charter in preparation.www.stormsurge.noaa.gov Regular coordination with NWS Marine Program Managers, both on Regional and National level to establish user needs. NOAA Coastal Storms Program (CSP) provides important developmental support: requirements set by means of stakeholder workshops, e.g. Pacific expansion (Van der Westhuysen et al., 2011) [PDF] and rip currents/wave runup products (Kurkowski et al., in prep).PDF Sandy Service Assessment (Sullivan & Uccellini 2013). Support from Sandy Supplemental (2013-2015) was essential in implementing NWPS on supercomputer and developing specific technical aspects of system. Support from NGGPS critical in ensuring integration of NWPS’s local-scale wave/surge model guidance within the next-generation global models.