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NAEFS is an international project combining global ensemble forecasts from Canada & USA to produce improved weather predictions. It provides earlier warnings, captures uncertainties, and offers seamless forecasts across borders. The system benefits from improved probabilistic forecast performance and accelerated implementation schedule. The project aims to accelerate improvements in 3-14 day forecasts by revolutionizing NWP processes with integrated, adaptive, and user-controllable systems.
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Edward O’Lenic1 and Zoltan Toth2 NOAA-NWS-1Climate Prediction Center 2Environmental Modeling Center Camp Springs, Maryland ed.olenic@noaa.gov 301-763-8000, ext 7528 NAEFS and the North American Week 2 Forecast
Overview of the North American Ensemble Forecast System (NAEFS) Prepared by Zoltan Toth Environmental Modeling Center NOAA/NWS/NCEP USA June 24, 2005 Acknowledgements: Louis Lefaivre, MSC, Canada http://wwwt.emc.ncep.noaa.gov/gmb/ens/index.html
OUTLINE • PARTICIPANTS • PROJECT DESCRIPTION • TIMELINE • IMPLEMENTATION SCHEDULE • CONCEPT OF OPERATIONS • BASIC PRODUCTS • END PRODUCTS • JOINT NCEP-MSC • WEEK 2 FORECAST
NAEFS ORGANIZATION Meteorological Service of Canada , MSC National Weather Service, USA, NWS National Meteorological Service of Mexico NMSM PROJECT OVERSIGHT Michel Beland, Director, ACSD Jean-Guy Desmarais, Director, AEPD Gilbert Brunet, MRB Louis Uccellini (Director, NCEP/NWS) Greg Mandt (Director, OST/NWS) Steve Lord, EMC PROJECT CO-LEADERS Louis Lefaivre (Implementation) -Zoltan Toth(Science) JOINT TEAM MEMBERS Meteorological Research Branch MRB Peter Houtekamer, Herschel Mitchell, Lawrence Wilson Canadian Meteorological Center CMC Yves Pelletier, Gerard Pellerin, Richard Verret, Alain Patoine, Manon Lajoie Environmental Modeling Center EMC Bo Cui, Richard Wobus, Yuejian Zhu NCEP Central Operations NCO: David Michaud / Brent Gordon / Scott Jacobs Climate Prediction Center CPC Ed O’Lenic, David Unger NWS Richard Grumm, Fred Branski
NAEFS is an international project to produce operational multi-center ensemble products Combines global ensemble forecasts from Canada & USA 80+ members per cycle, 2 cycles per day from MSC & NWS 6-hourly output frequency (instead of current 12-hourly) Replaces current 56 (16 MSC, 40 NCEP) members once a day setup Generates products for Intermediate users e.g., weather forecasters at NCEP Service Centers (US NWS) Specialized users e.g., hydrologic applications in all three countries End users e.g., forecasts for public distribution in Canada (MSC) and Mexico (NMSM) Prototype ensemble component of THORpex Global Interactive Forecast System (GIFS) Operational outlet for THORpex research using THORpex Interactive Grand Global Ensemble (TIGGE) archive
THORpex: THe Observing system, Research and prediction experiment A ten-year international research program aimed at accelerating improvements in deterministic and ensemble-probabilistic predictions of high-impact weather for both short range (up to 3 days) and medium range (4 to 14 days) time scales. Has four subprograms: Predictability research and numerical experimentation THORpex observing system tests, e.g., targeted observations, various weather types Global Field Campaign – 1 year in length (2009 or 2010) Includes all in-situ systems and available remote sensing systems Real-time data availability Includes all predictable time scales out to 14 days Societal and Economic Impact Assessment
ANTICIPATED BENEFITS Improved probabilistic forecast performance Earlier warnings for severe weather Lower detection threshold due to more ensemble members Uncertainty better captured via analysis/model/ensemble diversity A seamless suite of forecasts across International boundaries Canada, Mexico, USA Different time ranges (1-14 days) Development cost savings through Sharing scientific algorithms, codes, scripts Accelerated implementation schedule Low-cost diversity via multi-center analysis/model/ensemble methods Exchanging complementary application tools MSC focus on end users (public) NWS focus on intermediate user (forecaster) Production cost savings through Leveraging computational resources Each center needs to run only fraction of total ensemble members Providing back-up for operations in case of emergencies Use nearly identical operational procedures at both centers to provide basic products Offers as default basic products based on unaffected center’s ensemble
NOAA SERVICE GOAL: ACCELERATE IMPROVEMENTS IN 3-14 DAY FORECASTSNOAA SCIENCE OBJECTIVE: REVOLUTIONIZE NWP PROCESS NEW NWP Sub-systems developed in coordination End-to-end forecast process Strong feedback among components Two-way interaction Error/uncertainty accounted for TRADITIONAL NWP Each discipline developed on its own Disjoint steps in forecast process Little or no feedback One-way flow of information Uncertainty in process ignored SOCIOEC. SOCIOEC. SYSTEM SYSTEM INTEGRATED, ADAPTIVE, USER CONTROLLABLE
PROJECT HISTORY & MILESTONES February 2003, Long Beach, CA NOAA / MSC high level agreement about joint ensemble research/development work (J. Hayes, L. Uccellini, D. Rogers, M. Beland, P. Dubreuil, J. Abraham) May 2003, Montreal (MSC) 1st NAEFS Workshop, planning started November 2003, MSC & NWS 1st draft of NAEFS Research, Development & Implementation Plan complete May 2004, Camp Springs, MD (NCEP) Executive Review September 2004, MSC & NWS Initial Operational Capability implemented at MSC & NWS November 2004, Camp Springs Inauguration ceremony & 2nd NAEFS Workshop Leaders of NMS of Canada, Mexico, USA signed memorandum 50 scientists from 5 countries & 8 agencies March 2006, MSC & NWS 1st Operational Implementation Bias correction Climate anomaly forecasts March 2007, 2008, MSC, NWS Follow-up implementations Improved and expanded product suite
TENTATIVE IMPLEMENTATION SCHEDULE March 2006 1st NAEFS product suite NCEP operational web pages (incl. Caribbean & South American products) “Experimental” status for first 60 days NAWIPS grids for NCEP service centers, NDGD grids Feb 2006 Bias correction, Weighting, Climate anomaly (BWC) algorithms oprnl Dec 2005 BWC Codes/scripts delivered to NCO Nov 2005 Operational data exchange established Oct 2005 BWC Codes/algorithms exchanged between MSC-NCEP Sept 2005 Decision regarding BWC & Product implementation details
CONCEPT OF OPERATIONS Exchange ~50 selected variables Use GRIB2 to reduce volume of data Basic Products will be generated at both MSC and NCEP Same algorithms/codes used at both centers Duplicate procedures provide full backup in case of problems at either end If one component of ensemble missing, products based on rest of ensemble These form the basis for different sets of center-specific end products Ensures consistency between end products even if their format is different All basic products to be made available via ftp to user and research community Reduce systematic error through bias estimation Determine weights and combine MSC and NCEP ensemble Express forecast in terms of climatological anomalies Prepare & compare forecast with reanalysis climate distribution Generate center-specific end products – North American Week 2 Forecast Evaluate & provide feedback for improvements Verification using same algorithms User feedback
BASIC PRODUCTS NAEFS basic products Bias corrected members - 40 members, NAEFS variables, GRIB2 Bias correction against each center’s own operational analysis Create weights for each member for use in creating a distribution Weights depend on geographical location Climate anomaly percentiles for each member (non-dimensional) Allows downscaling of scalar variables to any local climatology Issues – Products to be added in future years Bias correction on precipitation and other variables Need reliable and bias-free satellite-based analysis of precipitation rates Collaborators needed – CPC (Janowiak), NESDIS? Climate anomalies exist for the15 most frequently used variables Need to use reanalysis data to describe climatology for rest of variables
END PRODUCTS Can be center specific Conform with procedures/requirements established at different centers End products generated at NCEP Based on prioritized list of requests from NCEP Service Centers End products generated at MSC TBD End products generated jointly Experimental probabilistic Week-2 forecast Fully automated, based on basic products: bias corrected, weighted climate anomalies Can become official product once performance reaches current operational level
NAEFS Week-Two Forecast Process Operational Analysis, O Multi-model ensembles from NCEP, CMC, Others Daily real-time observations Historical observations, Reanalysis, R Bias correction of 6-hourly model output with respect to operational analysis. Quantify systematic differences between the Operational Analysis and the Reanalysis, d*=R-O Adjust all forecasts by d* Compare forecasts to the Reanalysis-based climate PDF Basic products • Fully-automated weighted average 500-hPa 8-14-day mean height and anomaly forecast with spread End products Fully-automated T, P tercile probabilities Automated Dissemination
Forecast tools consolidation: ANOVA of Ensemble members and Gaussian Kernel Distribution Averaging Temperature (F)
Consolidation improves seasonal temperature outlooks by an average of 26%
North American 8-14-day Forecast T 26.7 % chance A, 33.3% chance N, 40 % chance B 40% chance A, 33.3% chance N, 26.7% chance B 33.3 to 30.05% chance A, 33.4 to 39.9% chance N, 33.3 to 30.05% chance B
8-14-day 500-hPa height and anomalies forecast – a weighted average of CFS, Canadian, other models
NAEFS & THORpex Expands international collaboration Mexico joined in November 2004 UK Met Office to join in 2006 Provides framework for transitioning research into operations Prototype for ensemble component of THORpex legacy forecast system: Global Interactive Forecast System (GIFS) RESEARCH THORpex Interactive Grand Global Ensemble (TIGGE) Transfers New methods Articulates operational needs North American Ensemble Forecast System (NAEFS) OPERATIONS
Discussions with other centers for expansion of NAEFS Experimental status - March 2006 Operational status – 2007-2008 UKMet – Agreement FNMOC, AFWA – Expert discussions Need to formalize, use operational centers’ forum (COPC) Product distribution Issues Name change from NAEFS to Global Ensemble Prediction Center Disc space requirements will grow Other centers that expressed interest in learning more about NAEFS ECMWF, NCMRWF, JMA, KMA Link with THORPEX Interactive Grand Global Ensemble (TIGGE) THORPEX research organized in 4 science Working Groups TIGGE data base supports ensemble-related research NAEFS – GEPS provides Testing in and transition to operational use Real time forecast data for demonstration projects EXPANSION OF NAEFS
Black : data presently exchanged Blue : items have been added in prototype script for expanded CMC dataset. Red : items can be easily added to the expanded dataset via an autoreq for CMC; next implementation period for NCEP * these will be added within 1 month for CMC ** these will be added within 2 months for CMC Green: items that require further consideration and resources LIST OF VARIABLES IDENTIFIED FOR ENSEMBLE EXCHANGE BETWEEN CMC - NCEP Parameter CMC NCEP Ensemble 8 SEF, 8 GEM GRID 2.5x2.5 deg, (144x73 lat-lon) [1.2 X 1.2 (300X151 lat-lon)] 1x1 deg (360x180 lat-lon) for day 1-7 2.5x2.5 deg (144x73 lat-lon) day 8-15 DOMAIN Global Global FORMAT WMO Grib Format WMO Grib Format HOURS 0, 12, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, 240 0, 12, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, 204, 216, 228, 240, 252, … 384 GZ [200], 250, 500, 700, 850,[925,1000] [200], 250, 500, 700, 850 ,[925],1000 TT [200], 250, 500,700, 850 ,[925,1000] [200], 250, 500, 700, 850 ,[925],1000 U,V [200], 250, 500,700, 850 ,[925,1000] [200], 250, 500, 700, 850 ,[925],1000 TT 12000 Now redefined in grib file to be 2m AGL 2m U,V Now redefined in grib file to be 10m AGL 10m ES 12000 Now redefined in grib file to be 2m AGL RH at 2m MSLP (PN) level 0, i.e. at surface PRMSL, i.e. at surface PR level 0, i.e. at surface level 0, i.e. at surface NT level 0 Total Cloud Cover IH level 0 Total Precipitable Water Sfc Pres (SEF) (P0) level 0 at surface Sfc Pressure Model Topography Model Topography Model Topography CAPE Sept 2004 June 2004 Precip type Sept 2004 Precip type Tmax June 2004 2m Tmin June 2004 2m WAM 2005-2006 2005-2006 Black : data exchanged in early 2004 Blue : items added to CMC and NCEP production by July 2004 Red : items added to CMC production by October 2004 Green: items in development (CMC) and testing (NCEP) by June 2005