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The NCEP Global and Regional Operational Numerical Guidance Systems 

William. M. Lapenta Acting Director Environmental Modeling Center NOAA/NWS/NCEP With contributions from many EMC Staff ……. The NCEP Global and Regional Operational Numerical Guidance Systems . Presentation Outline. The EMC Mission Importance of satellite data to NWP

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The NCEP Global and Regional Operational Numerical Guidance Systems 

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  1. William. M. LapentaActing DirectorEnvironmental Modeling CenterNOAA/NWS/NCEPWith contributions from many EMC Staff…… The NCEP Global and Regional Operational Numerical Guidance Systems 

  2. Presentation Outline The EMC Mission Importance of satellite data to NWP Global Forecast & Data Assimilation System Attributes Operational Requirements Data Assimilated Performance evolution since 1998 CONUS Mesoscale Model System Hybrid GSI Var-EnKF Assimilation System Upgrade Process

  3. The EMC Mission….. In response to operational requirements: • Develop and Enhancenumerical guidance • Improve NCEP’s numerical forecast model systems via: • Scientific upgrades • Optimization • Additional observations • Transition operational numerical forecast models from research to operations • Transform & integrate • Code • Algorithms • Techniques • Manages and executes transition process including technical and system performance review before implementation • Maintain operational model suite • The scientific correctness and integrity of operational forecast modeling systems • Modify current operational system to adapt to ever-present external changes EMC location within the funnel

  4. NWS Seamless Suite of ForecastProducts Spanning Weather and Climate Outlook Guidance Threats Assessments Forecast Lead Time Forecasts Watches Warnings & Alert Coordination Benefits NCEP Model Perspective Forecast Uncertainty Years Seasons Months • Climate Forecast System 2 Week • North American Ensemble Forecast System • Global Ensemble Forecast System 1 Week • Global Forecast System • Short-Range Ensemble Forecast Days Waves Real Time Ocean Forecast System • North American Mesoscale Hours • Rapid Update Cycle for Aviation Hurricane WRF & GFDL Space Weather Tsunami Minutes • Dispersion Models for DHS Health Aviation Recreation Ecosystem Agriculture Commerce Hydropower Environment Maritime Fire Weather Life & Property Energy Planning Reservoir Control Emergency Mgmt Space Operations

  5. Satellite Data is Required to Help Meet Key Performance Metrics • Numerical Weather Prediction • Global Anomaly Correlation Score – “Internal” metric • Related to ability to meet service-based metrics (below) • National Weather Service GPRA* Metrics (* Government Performance & Results Act) • Hurricane Track and Intensity Forecast Accuracy • Winter Storm Warning Lead Time and Accuracy • Precipitation Threat Accuracy • Flood Warning Lead Time and Accuracy • Marine Windspeed and Wave Height Forecast Accuracy • NAM and GFS are primary tools used by the NWS to meet the above goals

  6. Global Data Assimilation System (GDAS) Grid-point Statistical Interpolation (GSI) 3D-variational approach Unified system for all NCEP atmospheric applications Global (GDAS/GFS) Regional (NDAS/NAM) & HWRF Real Time Mesoscale Analysis (RTMA) Rapid Refresh (RR) Developed for operational application Forecasts must be completed within schedule Trade-offs More accurate formulation – higher resolution Improved model – improved analysis Enhanced physics – higher resolution Must work everywhere – all the time Manual intervention should be minimal Both operational and research data used in systems

  7. Assimilated Satellite Radiance Data GOES-11 Sounder: Thinned to 120km Channels 1-15 Individual fields of view 4 Detectors treated separately Over ocean only AMSU-A: Thinned to 60km NOAA-15 Channels 1-10, 12-13, 15 NOAA-18 Channels 1-8, 10-13, 15 METOP Channels1-6, 8-13, 15 AMSU-B/MHS: Thinned to 60km NOAA-15 Channels 1-3, 5 NOAA-18 Channels 1-5 METOP Channels 1-5 HIRS: Thinned to 120km NOAA-17 Channels 2-15 METOP Channels 2-15 AIRS: Thinned to 120km AQUA 148 Channels GOES-11 Sounder Channels 1-15 Individual fields of view 4 Detectors treated separately Over ocean only AMSU-A NOAA-15 Channels 1-10, 12-13, 15 NOAA-18 Channels 1-8, 10-13, 15 NOAA-19 Channels 1-7, 9-13, 15 METOP Channels 1-6, 8-13, 1 AQUA Channels 6, 8-13 AMSU-B/MHS NOAA-15 Channels 1-3, 5 NOAA-18 Channels 1-5 METOP Channels 1-5 HIRS NOAA-17 Channels 2-15 NOAA-19 Channels 2-15 METOP Channels 2-15 AIRS AQUA 148 Channels IASI METOP 165 Channels Global: All thinned to 145km Regional

  8. Assimilated Conventional Data and Satellite Products Satellite Products Conventional • Radiosondes • Pibal winds • Synthetic tropical cyclone winds and pressures(when needed) • Wind profilers • Conventional aircraft reports • ASDAR aircraft reports • MDCARS aircraft reports • Dropsondes • Surface land observations • Surface ship and buoy observation • Doppler radial velocities (regional) • VAD (NEXRAD) Winds • TAMDAR aircraft data • Mesonet data • MODIS IR and water vapor winds • GMS, METEOSAT and GOES cloud drift IR and visible winds • GOES water vapor cloud top winds • TRMM TMI precipitation estimates • GPS precipitable water estimates • GPS Radio occultation refractivity profiles • SBUV ozone profiles (other ozone data under test) • OMI total ozone 8

  9. Global Data Assimilation UpgradeQ3FY11—Late April Analysis Changes Recomputed background errors New version of CRTM 2.0.2 Improved Field of View calculation Updates for thinning and collocation calculations QC and obs. error and data handling updates for OMI AMSU-A (channel 5) ASCAT SBUV/2 ozone Ocean buoys New analysis options (useful for next round of development) Model Changes Thermal roughness length upgrade (X. Zeng, U. Arizona) Stratospheric tuning 5-Day 500MB NH AC 00Z Cycles 16 June-29 Sept 2010 Day 8

  10. 500-hPa Height AC Frequency Distribution, GFS 00Z Cycle Day-5 Forecast Southern Hemisphere 0.7 0.9 Northern Hemisphere 0.7 0.9 Poor forecasts (AC < 0.7) decrease Good forecasts (AC > 0.9) increase

  11. Percentage of Poor Forecasts 5-Day 500mb AC < 0.7 v.s. Model Upgrades AMSU-A & HIRS-3 data T126L28 (100km) to T170L42 (70km) Physics upgrade to prognostic cloud water, cumulus momentum transport T170L42 (70km) to T254L64 (55km) T254L64 (55km) to T382 (38km) OSU 2-L LSM to 4-L NOHA LSM T382L64 (38km) to T574L64 (27km) New shallow convection; updated SAS and PBL; positive-definite tracer transport

  12. Percentage of Good Forecasts 5-Day 500mb AC < 0.9 v.s. Model Upgrades T382L64 (38km) to T574L64 (27km) New shallow convection; updated SAS and PBL; positive-definite tracer transport Flow-dependent error covariance; Variational QC T254L64 (55km) to T382 (38km) OSU 2-L LSM to 4-L NOHA LSM T170L42 (70km) to T254L64 (55km) AMSU-A & HIRS-3 data

  13. NCEP Mesoscale Modeling for CONUS: Planned Q3 & Q4 FY11 NAM NEMS based NMM Bgrid replaces Egrid Parent remains at 12 km Multiple Nests Run to ~48hr ~4 km CONUS nest ~6 km Alaska nest ~3 km HI & PR nests ~1.5-2km DHS/FireWeather/IMET possible Rapid Refresh WRF-based ARW Use of GSI analysis Expanded 13 km Domain to include Alaska Experimental 3 km HRRR WRF-Rapid Refresh domain – 2010 RUC-13 CONUS domain Original CONUS domain Experimental 3 km HRRR

  14. Development of GSI Hybrid Var-EnKF • Test Period: 01 Aug to 22 September 2010 • Deterministic Forecasts: Operational GFS @ T574L64 • Ensemble Configuration: • 80 ensemble members • GSI for observation operators • T254L64 operational GFS • Initialized 00 UTC 15 July 2010 from interpolated GEFS members • allowed over 2 weeks spin-up • Assimilate all operational observations • Includes early (GFS) and late (GDAS/cycled) cycles • Operational prepbufr files (no prep/additional qc) • Dual-resolution/Coupled • High resolution control/deterministic component • Includes TC Relocation on guess • Ensemble is recentered every cycle about hybrid analysis • Throw out EnKF analyis mean • Bias correction (satellite) coefficients come from GSI/VAR • Minimal tuning done for hybrid • 1/3 static B, 2/3 ensemble

  15. 500 hPa SH AC Time Series6 Aug to 21 Sept 2011 Day 5 +0.026 AC Black – Control Red – Hybrid Green – Operational Day 6 +0.035 AC

  16. Process to Implement Major Upgradesto The NCEP Model Production Suite • Implementation Phase • SPA’s build NCO parallel from RFC’s • 30-day NCO parallel • Test code stability • Test dataflow • Products to NCEP Centers and EMC code developers • NCEP Centers • Evaluate impact • Assessments to NCEP OD R&D and Pre-Implementation Phase Systematic Testing • EMC Change Control Board • Scientific Integrity • Product Quality • EMC Mgmt Approval • 30-day NCO parallel stable • NCEP centers approve • Briefing to NCEP Director for final approval • Generate RFC’s • Submit RFC’s to NCO Implementation

  17. Schedule For the GFS/GSI December 2009 Implementation • 17 months required to develop, test and implement • 119 person months of effort (EMC, NCO, GFDL, TPC, SPC, HPC, AWC) • 17 months of continuous cycles 4/day with 16 day forecasts retrospective/real-time testing conducted for GFS/GSI • 500 HWRF and 600 GFDL TC/Hurricane cases simulated • 1000 Node hours and 75 TB of disk consumed

  18. Thanks for your time…

  19. Impact of Satellite Data on NWP….. Operational ECMWF system September to December 2008. Averaged over all model layers and entire global atmosphere. % contribution of different observations to reduction in forecast error. Note: 1) Sounders on Polar Satellites reduce forecast error most 2) Results are relevant for other NWP Centers, including NWS/NCEP Forecast error contribution (%) Courtesy: Carla Cardinali and Sean Healy, ECMWF

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