`Testing and evaluation of the GFS 2017


The global branch has completed real time and retrospective testing of the GFS 2017. The implementation has been approved by the director of NCEP. The global branch requested the active involvement of the rest of the National Weather Service in evaluating the GFS2017and has received very generous participation. The official request for evaluation with specific questions for evaluators is: http://www.emc.ncep.noaa.gov/gmb/noor/GFS2017/Eval_Letter_gfs2017_final.docx


Implementation is currently scheduled for June 20.


NCEP Director Briefing Feb. 21, 2017 http://www.emc.ncep.noaa.gov/gmb/noor/GFS2017/Q3FY17GFSOD20170221Final.pptx


EMC CCB Briefing Feb. 17, 2017 http://www.emc.ncep.noaa.gov/gmb/noor/GFS2017/CCBglobalFinal02172017a.pptx


Questions or comments please contact Glenn.White@noaa.gov or Vijay.Tallapragada@noaa.gov.


The experimental GFS implements:


a.         the NEMS software superstructure and infrastructure,

b.        upgraded land parameterizations and updated, higher resolution land surface climatologies that should improve near-surface fields and reduce patchiness seen in some cases,

c.         a fix to excessive cooling of 2m temperature during sunset,

d.        changes to cumulus convection parameterization that is expected to improve summertime precipitation forecasts,

e.         Near-Sea Surface Temperature that describes oceanic vertical temperature structure near surface due to diurnal warming and sub-layer cooling physics processes and that will improve SST, data assimilation and tropical weather forecasts,

f.           Rayleigh damping reduced by 50% in the upper stratosphere, and

g.        Assimilation of additional data and preparation for future satellites.


Retrospectives cover 5/20/2015-10/30/2016 and 5/11/2014-11/05/2014 and have been completed.  

The official real time began 10/18/2016.


Current schedule:


EMC has completed tests and evaluation.


Evaluation reports have been provided to EMC.


EMC director approved the implementation Feb. 17, 2017


The NCEP Director was briefed on February 21, 2017 and has approved the implementation.


There will be a separate 30 day evaluation for IT purposes only in April 2017.


GFS2017 would be implemented in June 2017.


Evaluation reports


Review of Evaluations http://www.emc.ncep.noaa.gov/gmb/noor/GFS2017/MEGMar217b.pptx


Storm Prediction Center

Evaluation letter http://www.emc.ncep.noaa.gov/gmb/noor/GFS2017/SPCevalletter.docx

Report http://www.emc.ncep.noaa.gov/gmb/noor/GFS2017/SPCreport.pptx


Climate Prediction Center

Evaluation letter http://www.emc.ncep.noaa.gov/gmb/noor/GFS2017/EvalLettergfs2017cpc.docx

Longer range forecasts http://www.emc.ncep.noaa.gov/gmb/noor/GFS2017/GFSpara2017Schemm.ppt

Stratosphere http://www.emc.ncep.noaa.gov/gmb/noor/GFS2017/GFS17EvaluationStratosphere2016.pptx


Weather Prediction Center

Evaluation letter http://www.emc.ncep.noaa.gov/gmb/noor/GFS2017/EvalLettergfs2017WPC.docx

Report http://www.emc.ncep.noaa.gov/gmb/noor/GFS2017/WPCGFSP2017evalv3.pptx


Ocean Prediction Center

Report http://www.emc.ncep.noaa.gov/gmb/noor/GFS2017/OPCEvaluationofGFSp.docx


Aviation Weather Center

Report http://www.emc.ncep.noaa.gov/gmb/noor/GFS2017/GFSv14AWCevaluation.docx


National Hurricane Center

Report http://www.emc.ncep.noaa.gov/gmb/noor/GFS2017/GFS2017evaluationNHC.pptx

Tropical storm genesis http://www.emc.ncep.noaa.gov/gmb/noor/GFS2017/GFS2017reviewTCgenesisa.pptx


Office of Water Prediction

Evaluation letter http://www.emc.ncep.noaa.gov/gmb/noor/GFS2017/EvalLettergfs2017OWP.docx


Meteorological Development Laboratory



Alaska Region

Evaluation letter http://www.emc.ncep.noaa.gov/gmb/noor/GFS2017/EvalLettergfs2017finalAR.docx


Western Region

Evaluation letter http://www.emc.ncep.noaa.gov/gmb/noor/GFS2017/WREvalLettergfs2017.docx


Southern Region

Evaluation letter http://www.emc.ncep.noaa.gov/gmb/noor/GFS2017/EvalLettergfs2017SR.pdf


Central Region

Evaluation letter http://www.emc.ncep.noaa.gov/gmb/noor/GFS2017/EvaluationCentralRegiongfs2017.docx


Eastern Region

Evaluation letter http://www.emc.ncep.noaa.gov/gmb/noor/GFS2017/EvalLettergfs2017finalER.docx


Resources for evaluators


The global branch plans to involve the field as in the last GFS2016 implementation.


The official request for evaluation with specific questions for evaluators is: http://www.emc.ncep.noaa.gov/gmb/noor/GFS2017/Eval_Letter_gfs2017_final.docx.


Guidance for the evaluation can be found in: http://www.emc.ncep.noaa.gov/gmb/noor/GFS2017/STMEGGBLDec216.pptx.


A VLAB forum for comments comparing the GFS and GFSX can be found at:

https://vlab.ncep.noaa.gov/web/emc-model-evaluation-group/home or https://vlab.ncep.noaa.gov/web/emc-model-evaluation-group.

This is intended as a site for communication on what evaluators and users see in their comparisons of the GFS and GFSX. EMC hopes to respond to the comments if appropriate.


A verification site for the entire test period is available at



Real time maps are available via Fanglin Yangs VSDB web site and the parallel MAG and via Western Region.


On the main verification page: http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/  daily precipitation verification maps for CONUS and other regions can be found by clicking PRECIP QPF on the upper left of the main page.

Synoptic maps for different regions can be found on the lower left under 2-D Maps. An archive of such maps can be found by clicking Archive or at http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/2Dgfsfcst/arch/. The current parallel is available from Oct. 25, 2016 on. 


Plume plots of the GFS and GFSX near surface fields for synoptic stations can be found at: http://www.emc.ncep.noaa.gov/mmb/cguastini/gfsx/EMCGFSXplumes.html


Plots comparing observed radiosonde soundings to soundings from the GFS are available at http://www.emc.ncep.noaa.gov/gc_wmb/tdorian/meg/index.html. Soundings from the GFSX are also available on the page. Hourly BUFR data including soundings from the GFSX out to 120 hours (and every 3 hours out to 240 hrs) have been developed.


Western Region map page for the GFS and GFSX is available: http://ssd.wrh.noaa.gov/gfs/html/


NCO mag eval site is available, showing in the GFS slot hourly output from the GFSX: http://mageval.ncep.noaa.gov/

These gfs plots can be compared with the operational GFS displayed in http://mag.ncep.noaa.gov/.


Quarter degree and half degree GFSX files are available on paraNOMADS: http://para.nomads.ncep.noaa.gov/pub/data/nccf/com/gfs/para/.


20 km AWIPS files for the parallel are available at



Gempak .25 and 1 degree files from the experimental GFS are available for the national centers.


Files from the real time parallel and 1 degree files from the retrospectives are on WCOSS.


GCWMB real time (prnemsrn) 2016101718-
Directory /gpfs/hps/emc/global/noscrub/emc.glopara/archive/prnemsrn

HPSS_GCWMB:  /5year/NCEPDEV/emc-global/emc.glopara/WCOSS_C/prnemsrn


GCWMB 2015 Summer retrospective (pr4rn_1505) 2015050100-2016010200 (246 days)


WCOSS directory  /gpfs/hps/emc/global/noscrub/emc.glopara/archive/pr4rn_1505

 HPSS_GCWMB:  /5year/NCEPDEV/emc-global/emc.glopara/WCOSS_C/pr4rn_1505


GCWMB 2015 Winter retrospective (pr4rn_1512) 2015121500-2016051518 (151 days)

WCOSS directory  /gpfs/hps/emc/global/noscrub/emc.glopara/archive/pr4rn_1512   

HPSS_GCWMB:  /5year/NCEPDEV/emc-global/emc.glopara/WCOSS_C/pr4rn_1512


GCWMB 2016 Summer retrospective (pr4rn_1605) 2016050100-2016103018 (184 days)

WCOSS directory  /gpfs/hps/emc/global/noscrub/emc.glopara/archive/pr4rn_1605
HPSS_GCWMB:  /5year/NCEPDEV/emc-global/emc.glopara/WCOSS_C/pr4rn_1605


GCWMB 2014 Summer retrospective (pr4rn_1405) 2014050100-2014110518 (189 days)

(to be completed by Feb. 6, 2017) This was run in two streams. The first stream is done.
WCOSS directory  /gpfs/hps/emc/global/noscrub/emc.glopara/archive/pr4rn_1405

WCOSS directory  /gpfs/hps/emc/global/noscrub/emc.glopara/archive/pr4rn_1408

HPSS_GCWMB:  /5year/NCEPDEV/emc-global/emc.glopara/WCOSS_C/pr4rn_1405


HPSS_GCWMB:  /5year/NCEPDEV/emc-global/emc.glopara/WCOSS_C/pr4rn_1408



monitoring/verification:  http://www.emc.ncep.noaa.gov/gmb/emc.glopara/vsdb/pr4rn_1408


Location of the GFS2016 files to compare to the GFS2017:


The current operational GFS was implemented on May 11, 2016 12Z. The

experimental runs above should be compared to the following GFS2016 data on WCOSS:




For the period 2015041506-201507218 /global/noscrub/emc.glopara/archive/pr4devbs15


For the period 2015070106-2016051906 /global/noscrub/emc.glopara/archive/pr4devb


For the period 2016051112 on /global/noscrub/emc.glopara/global/gfs


The global branch will work with evaluators to ensure they get the data they wish for their evaluations.


The global branch will again produce case studies requested by NCEP centers and NWS regional headquarters and field offices.  Please notify Glenn.White@noaa.gov and Tracey.Dorian@noaa.gov on what cases you would like to see.  




The global branch is doing statistical verification of forecast fields against analyses and observations, precipitation, 2m temperatures and dew points, and 10 m winds over CONUS and Alaska, and hurricane tracks and intensity.


A verification site for the entire test period is available at



The parallel GFS for the past month is plotted as the PRX on: http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/.


The verification of the real time parallel is at   http://www.emc.ncep.noaa.gov/gmb/emc.glopara/vsdb/prnemsrn/


The verification of the 2014 summer retrospective will be http://www.emc.ncep.noaa.gov/gmb/emc.glopara/vsdb/pr4rn_1405/





The verification of the 2015 summer retrospective is http://www.emc.ncep.noaa.gov/gmb/emc.glopara/vsdb/pr4rn_1505/.


The verification of the 2015/16 winter retrospective is http://www.emc.ncep.noaa.gov/gmb/emc.glopara/vsdb/pr4rn_1512/.


The verification of the 2016 summer retrospective is http://www.emc.ncep.noaa.gov/gmb/emc.glopara/vsdb/pr4rn_1605/.


The VLAB forum for comments comparing the GFS and GFSX can be found at:

https://vlab.ncep.noaa.gov/web/emc-model-evaluation-group/home or https://vlab.ncep.noaa.gov/web/emc-model-evaluation-group.

This is intended a site for communication on what evaluators and users see in their comparisons of the GFS and GFSX. EMC hopes to respond to the comments if appropriate.


Presentations on Evaluations of the GFSX


Comparison of GFS and GFSX global precipitation and systematic errors



GFS and GFSX Performance for Lisa, Gaston, Hermine Tracey Dorian



GFS and GFSX Performance in Anchorage, Alaska Tracey Dorian and Eugene Petrescu



GFS and GFSX precipitation comparison Glenn White



GFS and GFSX Systematic Errors Summer 2016 Glenn White



GFS and GFSX Systematic Errors Summer 2016 Tracey Dorian



GFS and GFSX Performance for Hurricanes Joaquin and Matthew Tracey Dorian



MODE verification of precipitation in GFS2017 Tracey Dorian



MODE verification of CAPE in GFS2017 Tracey Dorian



Global Branch statistical assessment of the GFS2017



Land surface team review of the GFS2017



Summary of case studies Tracey Dorian



Minnesota blizzard Corey Guastini



January 2016 blizzard Tracey Dorian



West Virginia flooding case study Tracey Dorian



Louisiana flooding case study Tracey Dorian



Hurricane Joaquin Precipitation Tracey Dorian



Evaluation of Hurricane Joaquin Tracey Dorian



Case studies proposed by Central Region Tracey Dorian



California precipitation Jan. 9, 10 2017 Tracey Dorian



MEG case studies including the experimental GFS:


Northeast snow event Feb. 9, 2017 Geoffrey Manikin




Northeast snow event Feb. 9, 2017 Tracey Dorian



California heavy precipitation event Feb. 17, 2017 Corey Guastini



Portland, Oregon heavy snow event Jan. 10,11, 2017 Geoffrey Manikin



Northern Plains blizzard Christmas 2016 Corey Guastini



West Coast storms Dec. 22-25, 2016 Glenn White



East Coast winter storm Jan. 7, 8, 2017 Tracey Dorian



West Coast storm Jan. 20-23, 2017 Corey Guastini



Tracey Dorian evaluation of Hurricane Matthew



Tracey Dorian evaluation of single forecast cases



Tracey Dorian evaluation of Hurricane Matthew



Tracey Dorian mode evaluation of jet streams



Tracey Dorian review of ocean cyclone of Feb. 8, 2016

http://www.emc.ncep.noaa.gov/gmb/noor/GFS2017/Feb 8, 2016 cyclone case study.pptx


Tracey Dorian review of case studies proposed by WPC and others MEG Dec. 15 http://www.emc.ncep.noaa.gov/gmb/noor/GFS2017/MEG GFS Parallel EvaluationsMEGDec15.pptx


Mallory Row comparison of radiation in the GFS2016 and GFS2017 with satellite observations http://www.emc.ncep.noaa.gov/gmb/noor/GFS2017/GCWMB_20161208.pdf

Website for her study http://www.emc.ncep.noaa.gov/gmb/mpr/


Preliminary evaluation of the GFS2017 at WPC map discussion Dec. 9

http://www.emc.ncep.noaa.gov/gmb/noor/GFS2017/EMC Fridaydec9a.pptx


Preliminary evaluation of the GFS2017 at MEG Dec. 1



New and old files


The global branch would like to


produce 1/8th degree files,

make them available for the first 36 hours via ftp for initial and boundary conditions for downstream modelers and

available on WCOSS for SPC for fire weather and for MDL for National Model Blend, and

stop distributing 2.5 degree files.


The 1/8th degree files will be worked after the scientific evaluation.


Presentations on changes to GFS


MEG presentation Nov. 10 reviewing GFS 2017 implementation plans and global branch verification pages http://www.emc.ncep.noaa.gov/gmb/noor/GFS2017/MEGnov10b.pptx

Presentations on land surface changes



Presentation on preventing decoupling of surface and atmosphere


Presentation on NSST


Presentations on cumulus convection changes



Presentations on NEMS



NEMS GFS benchmark tests before the final parallels were started:

1)  Benchmark forecast-only experiments initialized with current operational GFS initial conditions.  The NEMS GFS was configured to reproduce as closely as possible the non-NEMS operational T1534 GFS.

http://www.emc.ncep.noaa.gov/gmb/wx24fy/nems/nems7s/    JJA2015
http://www.emc.ncep.noaa.gov/gmb/wx24fy/nems/nems7w/    DJF 2015-16

2)  Benchmark cycled experiments with data assimilation.  Both GSI and  NEMS GFS were configured to reproduce as closely as possible the operational T1534 GFS.

http://www.emc.ncep.noaa.gov/gmb/wx24fy/nems/nems8s/    JJA2015
http://www.emc.ncep.noaa.gov/gmb/wx24fy/nems/nems8w/    DJF 2015-16

3) Google Doc from weekly NEMS GSM development meeting

4)  Briefings on NEMS GSM development: see the 8 ppts in