NCEP-EMC Global NWP Model VERIFICATION PACKAGE

Fanglin Yang

Modeling and Data Assimilation Branch
Environmental Modeling Center
National Centers for Environmental Prediction

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Credit and Acknowledgments

All scripts and Fortran programs except for those listed below are written and maintained by Fanglin Yang. Binbin Zhou and Geoff DiMego provided the script and code for grid-to-grid database computation. Jack Woollen and Suranjana Saha provided the script and code for making fit-to-obs maps. Perry Shafran and Geoff DiMego provided the Grid-to-Obs fortran programs. DaNa Carlis and Rebecca LaPorta developed the SCORECARD functionality. All third-party programs and scripts have been modified before being included in this package. Yuejian Zhu, Peter Caplan, and Bob Kistler had made significant contributions to a legacy system that was used to verify, monitor and archive GFS forecast skills before mid-2000s. A few of the Fortran source code used for precipitation verification and some of the climatology fields from the legacy system are still used in this verification package. A few "NWPROD" libraries were adopted from the GFS para system Shrinivas Moorthi updated and built on Zeus for running on different platforms. A few changes made by Jim Jung to the grid-to-grid Fortran source code were adopted to make the program compatible with Linux compilers. Shrinivas Moorthi helped with adding the script to port forecast data from different machines. Glenn White, Steve Lord and Xu Li made suggestions for creating and improving the significance test for AC dieoff curves and RMSE growth curves. Russ made a suggestion to include consensus analysis for verification. Helin Wei provided assistance for including the grid-to-obs verification. John Derber made a few suggestions to improve grid-to-obs verification, the SCORECARD and significane test graphics. Andrew Collard made a suggestion to include GDAS analysis increments. Rahul Mahajan proposed to include ENKF ensemble mean and ensemble spread maps. Many users have provided valuable comments and suggestions that helped improving the usability and portability of this package.

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This package performs the following verifications for NWP forecasts:

(1) AC, RMSE, BIAS etc: model forecasts are verified aganist analyses. Results are saved as partial sums in VSDB format; verification maps are then made to compare forecast verification metrics between different experiments and/or operational NWP models (up to 10 panels on one plot).

(2) QPF: precipitation threat skill scores over CONUS are first computed using either pgb or flx files as input and using either precip accumulation or precipiation rates as the verifiying variable; then precip threat skill score maps are made with Monte Carlo significance test being included.

(3) 2D MAPS: make maps of lat-lon distrubions and zonal mean vertical cross-sections to compare forecast fields, such as U,V,T,Q,RH,O3, T2m, Precip, etc.

(4) Fit-to-Obs: make fit-to-rawinsonde comparisions

(5) Grid-to-Obs: verifying forecasts against surface station observations and upper-air RAOBS

(6) Maps of GDAS/GFS analysis incrments

(7) Maps of ensemble mean and ensemble spread from GDAS/GFS ensemble forecasts

(8) transfer maps and web templates to web servers for display. Example: http://www.emc.ncep.noaa.gov/gmb/wx24fy/vsdb/gfs2016/ http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/

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Where to obtain the package

https://github.com/yangfanglin/gfs_verif

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How to install and use

(1)Users who plan to run verification jobs on NCEP WCOSS machines or NOAA RD computers only need to copy the driver vsdbjob_submit.sh and parameter setting script setup_envs.sh, make a few necessary changes as described within the two scripts, then execute the driver. NCEP WCOSS users who have passwordless links set up between WCOSS and emcrzdm should be able to post results directly to the web server (emcrzdm). Others can set up similar web displays, or may have to wait for all verification jobs to finish, then pack the ./web directory and transfer it to a web server for display.

(2)Users who plan to buid the package from scratch on different computer platforms need to get the tarball (vsdb_exp_v18.tar), unpack it, then check build.sh to see how to compile libraries and program executables based on platform options. Please also note that the climate data used for computing anomaly correlations are not included in this tarball, and additional observations may be required for computing precipitation QPF stats and grid-to-obs stats and for comparing forecasts with obs in 2D-MAPS section. Please contact me for these datasets.

(3)Please see http://www.emc.ncep.noaa.gov/mmb/mmbpll/misc/pwdless_ssh2.shtml.html for instructions of setting ssh keys and passwordless links.

============================================= Version Update Information

Version 22 information, July 2019

1. Add options for running verification on WCOSS_DELL
2. Add options for running verification on JET

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Version 21 information, July 2017

1. Change FHR from 12 bit to 14 bit in grid2obs ./parm/verf_gridtobs.prepfits.tab (L179) to increase maximum validation hours from 409.6 to 1638.4 hours (from Jeff Whiting).
2. Update grid-to-obs sfc verification to show stats for all 16 CONUS sub-regions instead of 7 aggerated areas.
3. Update grid2obs_plot.sh to use POE/MPMD on WCOSS (IBM and CRAY) computers to submit multiple jobs to one node up to each node's maximum processors. Each job processes one sub-region and for one field. This approach requires much less computing nodes and greatly speeds up the processing as well. "MPMD=YES" is the default.
4. Applied POE/MPMD to verify_exp_step2.sh as well for making AC/RMSE etc graphics. The original 49 serial jobs running on 49 shared nodes are now split into 93 jobs, submitted to 4 exclusive nodes, and run simultaneously. "MPMD=YES" is the default.
5. Updated scorecard.sh for BIAS significance test to account for sign changes.
6. After NAM update on 20March2017 the data assimilation was changed from a 12-h cycle with 3-h analysis updates to a 6-h cycle with hourly analysis updates. ndas prepbufr files were discontinued. grid2obs scripts were accordingly updated to use all NAM prepbufr files for surface verification.
7. Added verification against CERES and CLIPSO and update CAMS and GPCP to MAPS2D section made avaliable by Mallory Row.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Version 20 information, July 2016

1. Updated ./vsdb/precip to run precip verification against OBSPRCP in different format.
2. Updated scorecard to allow it to display stats for any given forecast days instead of fixed 6 days. User can modify day4card="1 3 5 6 8 10" in vsdbjob_submit.sh if they want to change the default setting.
3. Added an option to use 0.25-deg pgbq files from NEMS GFS for computing QPF ETS scores. Setting export ftyplist="pgbq" in vsdbjob_submit.sh switches to this option.
4. Added grid-to-obs verification to vsdbjob.sh, which is used by GFS parallels to generate verification on-the-fly stats in the vrfy step. Users need to add VRFYG2OBS=YES in their para_config to turn on this option. grid2obs vsdb data will be generated in vrfy.sh step and saved in vsdbsave directory.
5. Added THEIA as a new computer and updated all supporting scripts and data for THEIA.
6. Expanded grid-to-obs verification to include four GFS cycles.
7. Added the options to run on NCEP WCOSS CRAY supercomputers.
8. Added APRUN="aprun -n 1 -N 1 -j 1 -d 1" to run batch jobs on CRAY due to 3GB memory limit.
9. updated precip_score.f to allow incomplete records of precip scores to be used for making graphics. 10.NCO changed GFS output from /com to /com2 directory. Generalized all scripts to define COMROT directory from drivers. 11.Added an option to compute and display analysis increment using pgb files (pgbanl and pgbf06 from last cycle). The original version uses GFS sigma files (spectral coefficients) converted to lat-lon grids on model native vertical grid. The new NEMS GFS only writes model hisatory files in binary format on gaussian grid. Using pgb files does not require extra files to be saved and reduce the usage of disk space. 12.Generalied the grid option in verify_exp_step2.sh to use G2/G3/G4 or any grid users specified in setup_envs.sh. The prevous version only works for G2 grid.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Version 19 information, July 2015

1. Added a new tool for displaying ensemble mean and spread of GDAS/GFS ensemble forecasts.
2. Added a new tool for estimating GDAS/GFS analysis increments between siganl and sigges. A modified version of ss2gg was included in ~nwprod/util/sorc/s2g for converting sigma spectral coefficients to lat-lon binary files. The tool produces lat-lon and zonal-mean maps of time-averaged bias and RMS of analysis increments.
3. Added a program in vsdb/nwprod/util/sorc/mvgribdate.fd for modifying forecast file as an analysis file to allow users to use forecast as verification truth.
4. Added an option to allow forecasts to be verified aganist forecasts. Set "anl_type=fcst00" or "anl_type=fcst120" will force forecasts to be verified against pgbf00 or pgbf120.
5. Fixed a bug in grid2obs/verf_gridtobs_gridtobs.fd, in which GNH, GSH and GTRP are incorrectly defined (thanks to Bin Zhao from CMA).
6. Added an option to set pgbf00=pgbanl, which is required for models that use IAU (Incremental Analysis Update) technique. Set iauf00=YES in setup_envs.sh to turn on this option.
7. Added an option to allow users to specify experiment names (caplist) shown in AC and RMSE-type grahics differently from the names included in vsdb database. caplist defaults to mdlist.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Version 18 information, January 2015

1. Stan Benjamin from ESRL/NOAA found that the averaged RMSE shown in the t-p map does not always match the numbers printed in the RMS line plots. Redefined mrms in p-t plots as the average of rms time series instead of as root-mean square of mean variances sampled over all spatial and temporal space.
2. Extended precipitation verification from fixed 84 hours to any given forecast length. Added 2D-type maps to show ETS and BIAS scores for all forecast hours and all precip intensities.
3. It is uncovered that nonuniform sampling is used for computing precip skill scores in precip/sorc/precip_score.f. If one experiment has missing stats and much less samples than the other the computed mean ets and bias scores are not accurate.
4. Restructured 2D SfcMAP scripts. Added vardef.sh to define contour and color for all variables in 2D plots, changed all graphic format from gif to png to save disk space.
5. Added NCEP w3nco lib to make copygb work for grid 193 (0.25-deg).

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Version 17 information, April 2014

1. Updated grid-to-obs for running it on WCOSS and ZEUS. Source code was upgraded to /nwprod version, with modifications for global model application. Bufr lib was updated for reading prepbufr data generated on WCOSS. Scripts were updated to handle data retrieval from HPSS and transfer of graphics to web server in batch queues. WCOSS and ZEUS computing nodes have no access to HPSS and other computers.
2. In addition to ADPUPA, ANYAIR (AIRCAR and AIRCFT) is added to grid-to-obs upper air verification as an option. Sfc verification was updated to use 3-hourly fcst output for a better description of diurnal variation.
3. NASA S4 and JIBB users reported disk I/O problems when making some of the anom and pres grids. Thanks to Jim Jung and Doris Pan, the scripts under map_util have been modified to reduce I/O activities.
4. Added a new feature to generate scorecard using verification stats of AC, RMSE and Bias. It is developed by DaNa Carlis and Rebecca LaPorta. Setting "scorecard=Yes" in setup_envs.sh turns on this feature. Different symbols are used to represent student-t test significanes at the 95%, 99% and 99.9% levels. The test critical also varies with sample size. It is more stringent for smaller samples.
5. Updated fit2obs to fix mismatched global means in vertical and horizontal plots.
6. Updated vsdbjob.sh to run stats generation for all cycles only once per day. This script is used by the GFS parallel system to compute on-the-fly verification stats.
7. Updated scripts under ./map_util and ./precip to reset significance-test intervals to the upper and lower bounds of the map to force all hollow bars that depict significance levels to be plotted.
8. Removed the old "fits" directory. It has been replaced by the more advanced "fit2obs" verification tool developed by Jack Woollen and Suru Saha.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Version 16 information, July 2013

1. Added the options to run on NCEP WCOSS Tide and Gyre machines.
2. Added verification of sea-level pressure to grid-to-obs
3. Added the option to gather vsdb database from different directories/users.
4. Use batch queues to run 2D maps, and added more variables.
5. Added the option to place computation and data transfer on different nodes to allow graphics to be uploaded to servers using "transfer" queues (a requirement of NCEP WCOSS).
6. Updated the "fit-to-obs" verification to a new package developed by Jack Woollen, with certain contributions made by Suranjana Saha and Fanglin Yang. New features of the package include a) a new web display interface makes web browsing easier; b) multiple experiments/models (up to ten) can be included in one verification run. In the old version only two experiments/models were allowed. c) forecast hours to be verified are extended from previous 48 hours to any user specified hours.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Version 15 information, January 2013

1. Previous versins only allow forecasts to be verified at a 24-hour output interval. For instance, for 00Z 01Jan2012 fcst cycle, the verification is only done at the hours of 00Z01Jan2012, 00Z02Jan2012, 00Z03Jan2012, 00Z03Jan2012, and 00Z04Jan2012 etc. While for the 12Z 01Jan2012 fcst cycle, the verification is only done at the hours of 12Z01Jan2012, 12Z02Jan2012, 12Z03Jan2012, 12Z03Jan2012, and 12Z04Jan2012 etc. THIS UPDATE ALLOWS THE FORECASTS TO BE VERIFIED AT ANY GIVEN OUTPUT INTERVALS. For instance, for 00Z 01Jan2012 cycle, the verification can be done at a 6-hour interval, that is, at the hours of 00Z01Jan2012, 06Z01Jan2012, 12Z01Jan2012, 18Z01Jan2012, and 00Z02Jan2012 etc, as long as the observations/analyses are avaliable at these verificaiton hours. This update makes it possible to exam the diurnal variaiton of forecasts, and to apply this verification package for high-frequency short-range forecasts.
2. Updated the script to allow different cycles of the same forecast model to be verified at the same time. This is useful for inter-cycle comparison. For instance, by specifying fcycle="00 06 12 18" and mdlist="gfs" in vsdbjob_submit.sh the verification will compare the four cycles of GFS forecasts.
3. updated vsdb/plot2d scripts to speed up making 2D maps by a factor of four.
4. updated scripts under vsdb/map_util to speed up data mining by about 30 percent.
5. Updated the web page template vsdb_exp_webpage.tar. Earlier versions only work for the 00Z cycle of forecast. The new one works for all cycles.
6. The following programs and scripts are updated in this release: setup_envs.sh, vsdbjob_submit.sh, verify_exp_step1.sh, verify_exp_step2.sh, vsdb_exp_webpage.tar, plot2d/maps2d_new.sh, and almost all programs/scripts under ./exe and ./map_util.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Version 14 information, November 2012

1. Added ozone (O3) to the verification, including Bias and RMSE etc on six standard layers (100, 70, 50, 30, 20 and 10 hPa).
2. Updated precip verification (QPF) to include forecasts from the 12Z cycles. Previous versions can only handle 00Z-cycle forecasts.
3. Updated fits-to-obs programs to properly handle missing values. In previous versions, the program fails to make vertical profile plots if there is any missing value.
4. Updated fits-to-obs programs to use input data in either big_endian or little_endian format, or a mixture of both formats. Users need to specify input data format "endianlist" for each experiment in vsdbjob_submit.sh.
5. "No space" error occurs when running on Zeus with shared nodes. The "sub_zeus" command was updated to increase virtual memory.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Version 13 information, March 2012

1. Restructured the package so that it can be installed and used on different computer platforms. Some of the legacy fortan codes that only works on IBM CCS have been updated. Scripts have been modified to follow ksh standard. All data are written in big_endian format. This new package can be easily set up on different computer platforms by executing the newly added build.sh script and by modifying the newly added setup_envs.sh script.
2. Added "grid2obs" verification (so far only works on IBM CCS). It compares a) modeled T2m, RH2, WIND10m, Total cloud and cloud base height over the North America and its subregions with surface observations included in NDAS or NAM prepbufr files and, b) modeled T, Wind, Q, and RH over the globe its subregions with upper-air observations (e.g. rawinsonde, pibals, profilers, and ACARS etc) included in the NCEP operational GDAS prepbufr files. Please see http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/g2o/ as an example of this g2o verification. This part of verification has not been merged into the master driver vsdbjob_submit.sh. Users need to run grid2obs/grid2obs.sh to generate stats and then grid2obs/grid2obs_plot.sh to make graphics and to post results on web servers for display.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Version 12 information, Dec 2011

1. Added the capability of computing precipitation QPF skill scores (Previous versions require QPF skill scores as input and can only make graphics). The computation can be applied to 00Z and 12Z forecasts, using either pgb or flx files as input, with any precip bucket or without a bucket at all, and with any forecast output frequency and any forecast length. Set "CONUSDATA=YES" in vsdbjob_submit.sh turns on this option. Programs and scripts are saved under ./precip.
2. Added the option to remove missing data from all models/experiments so that the same number of samples is used to verify all members in the graphics. All programs and scripts under ./map_util have been changed to incorporate this option. Set "maskmiss=1" in vsdbjob_submit.sh turns on this option.
3. Added NWPROD to use user-defined libaries and utilities instead of pointing to NCEP CCS /nwprod. Copied the libaries and utilities under /nwprod that are used by this package to a local directory $sordir/nwprod. This change makes the package portable to different computer platforms.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Version 11 information, September 2011

1. Added an option to make maps of lat-lon distributions and zonal-mean cross-sections to compare forecasts among different experiments. A few selected fields are also compared with observations (mostly climatologies). This tool is particularily useful for detecting large changes and for code debugging. See MAPS2D in vsdbjob_submit.sh.
2. Added an option to verify all forecasts against ECMWF analysis.(set anl_type=ecmwf).
3. Allows users to choose the top of stats cross-section maps (set maptop=10, 50, or 100 hPa).
4. Corrected a bug in the source code for computing soil moisture stats (credit: George Gayno).
5. Corrected a bug in the source code for computing vector wind anomaly correction.
6. Allows users to verify forecasts to any given length. In previous versions the verification only works for up to 384 hours of forecasts.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Version 10 information, April 2011

1. Added anomaly correlation of sea-level pressure to the verification package.
2. Added verification metrics over the PNA (Pacific North America, 80E-320E, 20N-75N) region to the package. Users can also use the PNA slot as a template to display stats over a region of their own interest. What users need to do is to redefine the latitude and longitude boundaries of PNA given in exe/cntl_anom.sh and exe/cntl_pres.sh.
3. Added stats of area means of 18 surface variables over 12 sub-regions to the package. Changing the default "sfcvsdb=NO" in vsdbjob_submit.sh to "sfcvsdb=YES" will turn on this group of verification. It is sometimes useful for detecting differences of near surface quantities among different experiments.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Version 09 information, November 2010

1. Added a few new verification statistics, including Murphy's Mean-Squared Error Skill Score (MSESS), Ration of Standard Deviation, RMSE from Mean Difference, RMSE from Pattern Variation, and Anomalous Pattern Correlation. Updated web page template to display these metrics. Please see http://www.emc.ncep.noaa.gov/gmb/wx24fy/doc/RMSE_decomposition.pdf for definitions of these metrics and the advantange and disadvantage of each metric.

2. Added the option to verifiy all experiments against the same mean analysis (manl). "manl" is defined as the average of analyses of all experiments users select. It is computed on the fly before VSDB partial sums are derived. There are now four types of analyses users can use by setting anl_type in vsdbjob_submit.sh to, gfs : verified against each experiment's own GFS analysis, gdas : verified against each experiment's own GDAS analysis, canl : verified against common analysis, which is the mean of GFS, ECMWF and UKM operations, manl : verified against mean GFS analysis of the experiments selected.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Version 08 information, October 2010

1. Extended the top of RMSE and BIAS 2-D maps from 50 hPa to 10 hPa (Thanks to Glenn White for making the suggestion).
2. Modified the package to allow users to run applications on different computers, including vapor, with minimum changes to the scripts. Users only need to copy and modify vsdbjob_submit.sh.
3. Copied operational GFS daily fit-to-obs stats to vapor. Vapor users are now able to generate fit-to-obs plots to compare their own experiments with operational GFS. (Thanks to Suranjana Saha for making the operational stats available, and to Jia-Fong Fan for doing test on vapor).
4. Added the function to read precipitation QPF stats in FHO VSDB format, to compute precip ETS and Bias scores along with Monte Carlo significances, and to make GrADs plots. Please see the applicaiton template ./precip/plot_pcp_vsdb.sh. (Thanks to Ying Lin for providing VSDB FHO data and for helpful discussion).
5. Changed all graphic output format from "gif" to "png" (Portable Network Graphics) which has much smaller file size and better web display quality. Please see http://www.w3.org/QA/Tips/png-gif for a comparison between gif and pgn. Users who has been using my old web template need to use the updated vsdb_exp_webpage.tar. (Thanks to Xiujuan Su for making the suggestion)

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Version 07 information, 15 January 2010

Monte Carlo significance test has been added to the maps of precip skill scores. Please see the attached ppt file to see the methodology and examples. Only BIAS score and Equitable Threat Score are now included. The TSS Score in the previous package has been removed to enhance graphic presentation.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Version 06 information, 15 January 2009

1. Suru's fit-to-obs tool that compares forecasts with rawindsonde observations has been automated and added to the package.
2. Thanks to Moorthi, the package itself is now able to handle forecasts that are executed on different machines.
3. The master script vsdbjob_submit.sh has been modified and now is more flexible for turning on and off different verification components.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Version 04 information 10 July 2008

1. An option is added to allow the users to choose either the GFS analysis or GDAS analysis as the verification truth (observations). The option is called "anl_type" in vsdbjob_submit.sh. The default (previous) option is GFS analysis. My thank goes to Russ Treadon for his suggestion.
2. Confidence/uncertainty tests are added to the AC dieoff curves and RMSE error growth curves. For instance, in the bottom portions of the two plots attached to this mail the hollow bars indicate the 95% significance level, that is, those AC/RMSE differences falling outside of the bars are significantly different at the 95% significance level. My thanks go to Glenn and Steve for their suggestions.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Version 03 information

1. Thanks to Steve Lord and Xu Li, the dieoff curve of anomaly correlation has been amended to include the AC differences. Please see the attached sample plots. The yellow shading in the plots indicates whether or not the difference in AC between the first and second experiments is statistically significant. The null hypothesis is that AC1-AC2=0. The assumed distribution of AC1-AC2 is Guassian. This Gaussian assumption is valid for dealing with the difference of ACs, even though the distribution of AC itself is not Gaussian.
2. Scripts are added to automate the making and displaying of maps of precipitation skill scores over the CONUS.

Fanglin Yang, Ph.D.

fanglin.yang@noaa.gov

http://www.emc.ncep.noaa.gov/gmb/wx24fy/fyang/
http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/