On March 22, 2021, beginning with the 1200 Coordinated Universal Time (UTC) run, the National Centers for Environmental Prediction (NCEP) will upgrade the GFS and Global Data Assimilation System (GDAS) from version 15.3 to 16.0. As part of this upgrade, the previously standalone global deterministic WAVEWATCH III wave model Multi_1 will run coupled to the GFS forecast. GFS version 16.0 is the first major upgrade to the Finite Volume Cubed Sphere (FV3) dynamical core-based GFS, which replaced the spectral dynamical core in June 2019. In this upgrade, NCEP is increasing the number of model vertical layers from 64 to 127 and extending the model top from the upper stratosphere (~55 km height) to the mesopause (~80 km height). Changes include the following:

• Changes to the model components and physics
• Changes to the wave model
• Changes to the data assimilation
• Changes to product output products

1) Changes to the forecast model components and physics

• Updated Planetary Boundary Layer (PBL) scheme, namely a scale-aware Turbulent Kinetic Energy Based Moist Eddy-Diffusivity Mass-Flux (sa-TKE-EDMF) parameterization for vertical turbulent mixing.
• New parameterization of sub-grid scale gravity-wave physics.
• Updated radiation package to improve solar radiation absorption by water clouds and a revised cloud overlap assumption for radiation calculation.
• Revised ground heat flux calculation over snowpack.
• Improved cloud microphysics for computing ice cloud effective radius

2) Changes to the wave model

The current operational standalone global deterministic wave model Multi_1 (wave_multi_1.v3.3) will become a component in the GFS, coupled using a one-way scheme in which the atmospheric model provides winds to the WAVEWATCH III model. New features include a grid redesign, wave-current interaction and improved physics optimized to more frequent atmospheric forcing.

3) Changes to Data Assimilation

• Use observational precipitation to drive and spin up the uncoupled Global Land Data Assimilation System (GLDAS) in the GDAS cycle to provide more realistic land initial conditions
• Use a Local Ensemble Kalman Filter (LETKF) with model space localization and linearized observation operator to replace the Ensemble Square Root Filter (EnSRF)
• Apply a new 4-Dimensional Incremental Analysis Update (4D-IAU) technique
• Turn on Stochastic Kinetic Energy Backscatter (SKEB) scheme in GDAS ensemble forecasts
• Update variational Quality Control (QC)
• Apply Hilbert curve to aircraft data
• Update aircraft bias correction with safeguards
• Assimilate additional COSMIC-2 GNSS-RO data (COSMIC-2 E1 and E2)
• Apply correlated observation error for CrIS over sea surfaces and IASI over sea and land
• Assimilate AMSU-A channel 14 and ATMS channel 15 without bias correction
• Assimilate CSR data from ABI_G16, AHI_Himawari8, and SEVIRI_M08
• Assimilate AVHRR from NOAA-19 and Metop-B for near sea-surface temperature (NSST)
• Assimilate high-density flight-level wind, temperature, and moisture observations in tropical storm environment
• Upgrade to Community Radiative Transfer Model (CRTM) v2.3.0

4) Changes to directory structures on the NCEP Web services

WAVEWATCH III multi_1 products found on NOMADS/ftpprd in pub/data/nccf/com/wave/prod/
will be replaced by GFS.v16 Wave products and moved to the GFS directory structure for NOMADS/ftpprd:
pub/data/nccf/com/gfs/prod/

With this upgrade, the following changes occur on either the NCEP web services:
https://nomads.ncep.noaa.gov/pub/data/nccf/com/
ftp://ftpprd.ncep.noaa.gov/pub/data/nccf/com/
or on the NWS Web services:
https://tgftp.nws.noaa.gov/SL.us008001/ST.opnl/
ftp://tgftp.nws.noaa.gov/SL.us008001/ST.opnl/

• Atmospheric output:
• pub/data/nccf/com/gfs/prod/gfs.YYYYMMDD/CC/atmos
• pub/data/nccf/com/gfs/prod/gdas.YYYYMMDD/CC/atmos
• pub/data/nccf/com/gfs/prod/enkfgdas.YYYYMMDD/CC/atmos
• Wave output:
• pub/data/nccf/com/gfs/prod/gfs.YYYYMMDD/CC/wave
• pub/data/nccf/com/gfs/prod/gdas.YYYYMMDD/CC/wave

where YYYYMMDD is year, month, and day and CC is cycle.

5) Changes to the output file names on the NCEP Web services

• GFS native grid files: The format of GFS analysis and forecast history files is changed from nemsio (binary) to netcdf, including a change of file extension. For example:
  • gfs.tCCz.atmanl.nemsio --> gfs.tCCz.atmanl.nc
  • gfs.tCCz.sfcanl.nemsio --> gfs.tCCz.sfcanl.nc
  • gfs.tCCz.atmfHHH.nemsio --> gfs.tCCz.atmfHHH.nc
  • gfs.tCCz.sfcfHHH.nemsio --> gfs.tCCz.sfcfHHH.nc
  Where CC is 00, 06, 12, 18, and HHH is 000-012
• GDAS native grid files: The format of GDAS analysis and forecast history files is changed from nemsio (binary) to netcdf, including a change of file extension. For example:
  • gdas.tCCz.atmanl.nemsio --> gdas.tCCz.atmanl.nc
  • gdas.tCCz.sfcanl.nemsio --> gdas.CCz.sfcanl.nc
  • gdas.tCCz.atmfHHH.nemsio --> gdas.tCCz.atmfHHH.nc
  • gdas.tCCz.sfcfHHH.nemsio --> gdas.tCCz.sfcfHHH.nc
  Where CC is 00, 06, 12, 18, and HHH is 000-012
• ENKFGDAS native grid files: The format of EnKF forecast history files is changed from nemsio (binary) to netcdf, including a change of file extension. For example: gdas.tCCz.sfcfHHH.nemsio --> gdas.tCCz.sfcfHHH.nc
• WAVE grib2 files: The output grib2 file names change to align with the rest of the GFS.
  • Prefix changes from multi_1 to gfswave or gdaswave
  • Grid resolution naming convention changes and some products replaced by new output
    • glo_30mext --> global.0p25
    • glo_30m --> global.0p16, gsouth.0p25
    • at_10m --> atlocn.0p16
    • wc_10m --> wcoast.0p16
    • ak_10m --> arctic.9km
    • ep_10m --> epacif.0p16
    Example: multi_1.glo_30mext.t00z.f000.grib2 -> gfswave.t00z.global.0p25.f000.grib2
• GFSWAVE bulletin and spectra tar files: The station output names will change with the prefix going from multi_1 to gfswave for the wave bulletin and spectra tar files. Example:
  multi_1.t12z.spec_tar.gz-> gfswave.t12z.spec_tar.gz
• GTG turbulence: The file that contained the GTG turbulence will be replaced by a file with both GTG turbulence and icing severity:
  gfs.tCCz.gtg.0p25.fFFF.grib2 -> gfs.tCCz.wafs_0p25.fFFF.grib2

6) Changes to Variables on the NCEP Web services

• The following changes will be made to GFS station BUFR soundings:
  • Remove station elevation adjustment from grid terrain to station terrain. When model grid terrain height is different from station elevation, temperature, humidity and pressure were adjusted to the station surface in GFS V15. This adjustment is removed in GFS V16.
  • Correct unit and values for surface evaporation. The values and units of the net surface evaporation in GFS V15 is actually the surface latent heat net flux with unit of (W m-2). The values have been changed to net surface evaporation with units of kg/m**2.
  • Replace nearest neighbor grid point for bufr station HILO (Hilo, Hawaii) with a better-represented grid point with similar terrain height and profile to the station. This update was made after extensive investigation. The original grid point is located to the west of the station (lat/lon: 19.73967/204.8438); the new grid point is to the south (lat/lon: 19.62252/204.9609).
  • Add bufr station character IDs to the sounding files in the header section.
• Update atmospheric pressure GRIB (pgrb2) files as follows:
  • Unify all 3-D fields to have the same 41 standard isobaric layers for all forecast hours, including analysis time.
  • Add seven more pressure levels (at 0.01, 0.02, 0.04, 0.07, 0.1, 0.2, 0.7 hPa) for all isobaric fields in the upper stratosphere and the mesosphere
  • Add several new variables including cloud ceiling height (HGT), instantaneous total column cloud fraction (TCDC), instantaneous cloud fraction (LCDC/MCDC/HCDC) at low/middle/high cloud, 1 and 4 km radar reflectivity (REFD), radar reflectivity (REFD) at model layer 1 and 2, mixed layer convective available potential (CAPE) and convective inhibition (CIN), plant canopy surface water (CWAT), soil moisture (SOILL) at 0-0.1, 0.1-0.4, 0.4-1,1-2 m below ground level, sea ice thickness (ICETK), surface roughness (SFCR), sea ice skin temperature (ICETMP), soil type (SOTYP), vegetation type (VEG) and frictional velocity (FRICV).
  • Remove the legacy field 5-wave height (5WAVE), one of the two land-sea masks LANDN, and the icing severity. The icing severity will be moved to the new file: gfs.tHHz.wafs_0p25.fFFF.grib2.
  • Replace the land-sea mask (LAND) obtained via nearest neighbor interpolation with the one interpolated via bi-linear interpolation.
  • Replace filtered Shuell Sea Level Pressure with unfiltered one using the same ID (PRMSL). The heavily filtered Shuell Sea Level has caused confusion to users due to its inconsistency with the 10m wind field.
  • Change labeling of time averaged cloud fraction at low/middle/high clouds from TCDC to LCDC, MCDC, HCDC.
  • Increase GRIB precision for several variables. A complete list can be found here.
  • Remove all isobaric specific humidity fields (SPFH) from atmospheric pressure GRIB backup (pgrb2b) files. A subset of these isobaric specific humidity fields have been moved to pgrb2 files; SPFH at the following pressure levels have been removed: 125 hPa to 975 hPa every 50 hPa.
  • Replace legacy synthetic nadir GOES 12/13 with synthetic nadir ABI GOES-R in the following files: gfs.tCCz.goessimpgrb2fFFF.grd221
  • Remove lifted index (LFTX) from the surface flux (sfluxgrb) files; users may get this field from pressure GRIB (pgrb2) files.
  • Change the Grib2 master table version number from 2 to 6 for all variables in gfs.tCCz.wafs_grb45fFF.grib2

7) Additions to Product and Files on NCEP Web Services

• New parameters are included in the gfswave grib2 output files:
  • Significant wave height of third swell partition (SWELL:3)
  • Mean wave period of third swell partition (SWPER:3)
  • Mean wave direction of third swell partition (SWDIR:3)
• Add gdas.tCCz.crisf4.tm00.bufr_d files containing level 1B radiance data from the S-NPP/N20 CrIS instrument. The previously available CrIS data was discontinued by the upstream provider in early 2020.
• Add the new file gfs.tHHz.wafs_0p25_unblended.fFF.grib2 to be used by UK Metoffice to produce blended WAFS products. The file contains icing severity and GTG turbulence on limited ICAO standard levels of exact numbers, as well as CB field.
• Add the station time series BUFR station lists. The new stations are:
  • 048327 18.77N 98.96E VTCC CHIANG MAI, THAILAND
  • 048381 16.47N 102.78E VTUK KHON KAEN, THAILAND
  • 048400 15.77N 100.14E VTPN NAKHON SAWAN, THAILAND
  • 048407 15.25N 104.87E VTUU UBON RATCHATHANI, THAILAND
  • 048453 13.67N 100.61E BKK BANGKOK THAILAND
  • 048568 7.19N 100.61E VTSH 10 SONGKHLA, THAILAND
• Add new consolidated aviation file: gfs.tHHz.wafs_0p25.fFFF.grib2 containing GTG turbulence and icing severity.
• Change the grib2 parameter of icing severity changed from 234 to 37 and the mnemonic from ICSEV to ICESEV.
• Interpolate Icing Severity and Turbulence products onto ICAO standard levels of reference numbers instead of standard pressure levels.

8) Removal/Replacement from NCEP Web Services:

• Replace legacy synthetic nadir GOES 12/13 on global 1 degree grid with synthetic nadir ABI GOES-R products on global .25 degree grid. Remove gfs.tCCz.goessimpgrb2.1p00.fFFF and replace with gfs.tCCz.goessimpgrb2.0p25.fFFF
• Remove WAFS blended product at 1.25 deg: WAFS_blended_YYYYMMDDHHfFF.grib2
• Remove Wave Products with replacements where noted:
  • All products from legacy grids: akw, enp, wna, nww3
  • All 4-arcmin grib2 data files: ak_4m, at_4m, wc_4m
  • Binary forcing files (icean_5m, gfs_30m, aoc_15m)
  • CSV bulletins (csbull)
  • multi_1.glo_30m.tCCz.fFFF.grib2 removed, replaced by
    • gdaswave.tCCz.global.0p16.fFFF.grib2,
    • gfswave.tCCz.global.0p16.fFFF.grib2,
    • gdaswave.tCCz.gsouth.0p25.fFFF.grib2, and
    • ggfswave.tCCz.gsouth.0p25.fFFF.grib2
  • multi_1.at_10m.tCCz.f???.grib2 removed, replaced by gdaswave.tCCz.atlocn.0p16.fFFF.grib2 and gfswave.tCCz.atlocn.0p16.fFFF.grib2
  • multi_1.wc_10m.tCCz.f???.grib2 removed, replaced by gdaswave.tCCz.wcoast.0p16.fFFF.grib2 and gfswave.tCCz.wcoast.0p16.fFFF.grib2
  • multi_1.ep_10m.tCCz.f???.grib2 removed, replaced by gdaswave.tCCz.epacif.0p16.fFFF.grib2 and gfswave.tCCz.epacif.0p16.fFFF.grib2
  • multi_1.ak_10m.tCCz.fFFF.grib2 removed, replaced by gdaswave.tCCz.arctic.9km.fFFF.grib2 and gfswave.tCCz.arctic.9km.fFFF.grib2
  • multi_1.glo_30mext.tCCz.fFFF.grib2 removed, replaced by gdaswave.tCCz.global.0p25.fFFF.grib2 and gfswave.tCCz.global.0p25.fFFF.grib2

9) Product Timing and Volume Changes

• Increase in data volume of the pgrb2 files by approximately 55% per file.
• Increase in data volume of sflux files by approximately 29%.
• Increase in data volume of pgrbfull files by approximately 32%
• Decrease data volume of pgrb2b files by approximately 5%
• Increase data volume of each bufr station from 100kb to 190kb; Increase AWIPS collective files size by about 90%.
• Delay in the delivery of the GFS atmos pgrb2 output for all resolutions, starting at 8 minutes for forecast hour 000 and growing to 11 minutes for forecast hour 384
• Delay in the delivery of GDAS atmos pgrb2 output by up to 26 minutes
• Delay in the delivery of GDAS ensemble (ENKF) atmos output 19 to 23 minutes
• Delay in the delivery of Synthetic GOES products gfs.tHHz.goessimpgrb2.0p25.fFFF files by up to 14 minutes
• Delay in the delivery of WAFS product gfs.tHHz.wafs_grb45fFF.grib2 by 21 minutes
• Delay in the delivery of gfs.tCCz.wafs_0p25.fFFF.grib2 by up to 21 minutes, which replaces the GTG turbulence product gfs.tCCz.gtg.0p25.fFFF.grib2
• Delay in the delivery of WAFS wafsgfs_L_tCCz_intdskFF.grib2 and wafsgfs_P_tCCz_intdskFF.grib2
• Delay in the delivery of BUFR sounding products by up to 8 minutes
• Delay in the delivery of the wave spectra and bulletin files (gfswave.tHHz.spec_tar.gz, gfswave.tHHz.bull_tar, gfswave.tHHz.cbull_tar) by up to 85 minutes due to the increase in wave forecast from 180 to 384 hours.

10) Removal of products from NOAAPort/SBN

• 5 wave height (5WAVH) legacy variable from AWIPS products: 20km grids (CONUS, Alaska, Puerto Rico, Pacific region) and LAT/LON 1.0 degree grid
• U and V winds and temperature in wintemv legacy bulletin format for select levels: 850mb, 700mb, 500mb, 400mb, 300mb,250mb, 200mb, 150mb, 100mb
• Ship information in navybull legacy bulletin
• U and V winds, temperature, height, relative humidity in gridbuls legacy bulletin
• Gridded wind-waves from AWIPS products including Alaska 10-arcmin, Alaska 4-arcmin, Atlantic 4-arcmin and West Coast 4-arcmin. The Alaska grids will be replaced by the Arctic 9km grid.
• Gridded wave steepness (wstp) AWIPS products for all domains.
• Legacy NWW3 grids in grib1 format
• All WMO headers proposed for removal are listed here.

On June 12, 2019, beginning with the 1200 Coordinated Universal Time (UTC) run, the National Centers for Environmental Prediction (NCEP) will upgrade the GFS Analysis and Forecast System as follows:

• Changes to the model components (new dynamic core)
• Changes to the data assimilation
• Changes to the post-processing
• Changes to output products

1) Changes to the Global Forecast System Forecast Model

NOAA/NWS selected the finite volume cubed-sphere (FV3) dynamical core as the Next Generation Global Prediction System (NGGPS). The FV3 was developed by the Geophysical Fluid Dynamics Laboratory (GFDL) under NOAA's Office of Atmospheric Research (OAR). The prevous operational GFS, which has a spectral dynamical core, will be upgraded with the FV3 dynamical core and improved physics parameterizations.
GFS version 15.1 maintains a horizontal resolution of 13 km, and has 64 levels in the vertical extending up to 0.2 hPa. It uses the same physics package as the current operational GFS except for:

• The replacement of Zhao-Carr microphysics with the more advanced GFDL microphysics
• An updated parameterization of ozone photochemistry with additional production and loss terms
• A newly introduced parameterization of middle atmospheric water vapor photochemistry
• A revised bare soil evaporation scheme, e) a modified convective parameterization scheme to reduce excessive cloud top cooling.

EMC conducted 3-years of retrospective experiments, including the real-time parallel, covering the past three and half years for a comprehensive evaluation of the FV3GFS implementation. It shows equal or improved forecast skills in many areas, especially for 500-hPa height anomaly correlations, precipitation diurnal cycle and ETS score over the CONUS, stratospheric ozone and water vapor, and hurricane intensity over all basins.

2) Changes to Data Assimilation

• Add Infrared Atmospheric Sounding Interferometer (IASI) moisture channels
• Add Advanced Technology Microwave Sounder (ATMS) all-sky radiances
• Add Megha-Tropiques SAPHIR data
• Add Advanced Scatterometer (ASCAT) data from MetOp-B
• Add Meteosat-11 SEVIRI channels 5 and 6
• Add NPP OMPS profile and total column ozone
• Monitor NOAA-19 SBUV/2, Metop-C AMSUA and MHS, GOES-17 AMVs
• Add ability to read drifting and moored buoy data
• Update quality control for GOES atmospheric motion vector (AMV) winds
• Upgrade the use of Cross-Track Infrared Sounder (CrIS) radiances
• Upgrade specific humidity perturbation and statistics physics tendency perturbation with new parameter settings in ensemble forecast. Statistical kinetic energy backscattering perturbation is excluded
• Remove digital filter and storm relocation
• Increase horizontal resolution of the ensemble part of the hybrid data assimilation from 35 km to 25 km
• Update the Near Sea Surface Temperature scheme to a) apply Sea Surface Temperature climatology tendency to the foundation temperature and, b) reduce background error correlation length from 450~800 km down to 100 km.

3) Changes to directory structures on the NCEP Web services
Major change to the GFS, GDAS and EnKF sub-directory structure:

• gfs.YYYYMMDDCC -> gfs.YYYYMMDD/CC
• gdas.YYYYMMDDCC -> gdas.YYYYMMDD/CC
• enkf.YYYYMMDD/CC -> enkfgdas.YYYYMMDD/CC

where YYYYMMDD is year, month, and day and CC is cycle.
The EnKF sub-directory structure is changing where each member is a unique directory. enkf.YYYYMMDD/CC/FILE -> enkfgdas.YYYYMMDD/CC/memXXX/FILE
Where XXX is the member from 001, 002, ...080.

4) Changes to the output file names on the NCEP Web services

• The EnKF files will no longer include memXXX in the file name, that information will now be obtained from the sub-directory. gdas.tCCz.sfcf009.memXXX.nemsio -> memXXX/gdas.tCCz.sfcf009.nemsio
• The Surface Flux (sflux) file name will change to include a leading "0" for forecast hours below 100, which will match all other file naming structures. Name changes are as follows:
• gfs.tCCz.sfluxgrbfFF.grib2 -> gfs.tCCz.sfluxgrbfFFF
• gdas.tCCz.sfluxgrbfFF.grib2 -> gdas.tCCz.sfluxgrbfFFF Where FF and FFF are the two and three digit forecast hours.
• The GDAS near sea-surface temperature analysis nemsio file (gdas.tCCz.nstanl.nemsio) will be merged into the surface analysis nemsio file (gdas.tCCz.sfcanl.nemsio).

5) Changes to Variables on the NCEP Web services

• Time averaged and accumulated max/min variables will be removed from surface flux (sflux) files at forecast hour 000, as these fields do not have physical meaning at this time step.
• The sflux files will have additional variables for forecast 000 only. These variables already exist in later forecast hours.
• These pressure GRIB (pgrb) files will have both variable and level additions.
  • gfs.tCCz.pgrb2.1p00.fFFF
  • gfs.tCCz.pgrb2.0p50.fFFF
  • gfs.tCCz.pgrb2.0p25.fFFF
  • gfs.tCCz.pgrb2b.0p50.fFFF
  • gfs.tCCz.pgrb2b.0p25.fFFF
  • gfs.tCCz.pgrb2b.1p00.fFFF  
• The following changes will be made to GFS station BUFR soundings:
  • Only non-hydrostatic vertical velocity VVEL (cm/s) will be included. Hydrostatic vertical velocity OMEGA (Pa/s) will be removed.
  • A new bufr sounding station will be added (999390 40.19N, 113.47W DGWY 11 Dugway Prov Grd Ld 1296).
  • The elevation at Station (488100 22.82N 104.97E 11 HA GIANG VIETNAM 117) will be changed from 10 m to 117 m.

6) Product and File Additions to NCEP Web Services
NCEP wants to highlight two potentially impactful changes to the vertical velocity (VVEL) and accumulated precipitation (APCP) variables. To keep in line with the direction of the NCEP modeling suite unification these variables are changing. In order to provide users with enough lead time, both the legacy and new variables will be included in GFS V15. We encourage users to migrate to the new variables described below. In the near future, the legacy products will be removed.

• A second vertical velocity field will be included in the output files and written out by the model as DZDT (m/s). The FV3 GFS treats DZDT as a prognostic variable. The vertical velocity VVEL (pascal/s) found in the current operational product is now derived from DZDT using the hydrostatic approximation.
• New total precipitation and convective precipitation, with continuous accumulation, will be added to the output. Examples of the new variables:
  • APCP:surface:0-10 day acc fcst
  • ACPCP:surface:0-10 day acc fcst
• The following output files will have increased temporal resolution from 12-hly to 3-hly after forecast hour 240 (FFF=forecast hour greater than 240):
  • gfs.tCCz.pgrb2.1p00.fFFF
  • gfs.tCCz.pgrb2.0p50.fFFF
  • gfs.tCCz.pgrb2.0p25.fFFF
  • gfs.tCCz.pgrb2b.0p50.fFFF
  • gfs.tCCz.pgrb2b.0p25.fFFF
  • gfs.tCCz.pgrb2b.1p00.fFFF
  • gfs.tCCz.sfluxgrbfFFF.grib2
• A new cyclone tracker file will be added to the NCEP Websites. It contains three parameters for depicting cyclone phases based on Hart (2003), where parameter B for cyclone thermal symmetry and parameters -Vt(lower) and -Vt(upper) for cyclone thermal winds. File will be located under directory structure:
  • com/ens_tracker/prod/gfs.YYYYMMDD/CC/tctrack, with file name: avnop.tCCz.cyclone.trackatcfunix

7) Product Removal from NWS Web Services, with Substitutes on the NCEP Web Services:

• The 0.5 degree files labeled for the National Polar-orbiting Operational Environmental Satellite System (NPOESS) will be removed. Users can find replacement files on the NCEP Websites. File names that will be removed match: fh.0FFF_tl.press_gr.0p5deg_pt.npoess. Replacement files on the NCEP Web services:
  • gfs/prod/gfs.YYYYMMDD/CC/gfs.tCCz.pgrb2.0p5.fFFF
  • gfs/prod/gfs.YYYYMMDD/CC/gfs.tCCz.pgrb2b.0p5.fFFF
• The GFS NEMSIO files will be removed from NWS Web services. File names that will be removed:
  • ST.expr/MT.gfs_CY.CC/RD.YYYYMMDD/PT.bin_DF.of fh.anal_tl.sigma
  • ST.expr/MT.gfs_CY.CC/RD.YYYYMMDD/PT.bin_DF.of fh.anal_tl.sfsig
  • Exact replacement files on the NCEP Web services:
    • gfs.YYYYMMDD/CC/gfs.tCCz.atmanl.nemsio
    • gfs.YYYYMMMDD/CC/gfs.tCCz.sfcanl.nemsio
• The cyclone tracker file on the NWS Website will be moved to the NCEP Website. This file provides the basic hurricane track information such as location and intensity. The names that will be removed: avn.tCCz.cyclone.trackatcfunix. Exact file replacement path on NCEP Web services: ens_tracker/prod/gfs.YYYYMMDD/CC/tctrack/

8) Product Removal from NCEP Web Services

• The ENKF atmospheric analysis for each ensemble member will be removed from the NCEP Web services with file names like:
  • gdas.tCCz.ratmanl.memFFF.nemsio
  • gdas.tCCz.atmf006s.memFFF.nemsio
  • gdas.tCCz.atmf009s.memFFF.nemsio

9) Product Timing and Volume Changes

• The data volume per file will increase for most output. This includes about 50% increase in the "pgrb2" and "pgrb2b" files and up to a 200% increase in the "nemsio" files.
• The previous operational GFS V14 ran at a coarser horizontal resolution beyond forecast hour 240, while GFS V15 run at the same high resolution throughout the entire forecast length up to 384 hours. As a result, the delivery of all GFS products after 240 hours of forecast will be delayed. The last products at forecast hour 384 will be delayed by up to 18 minutes.
• Due to restructuring of some model processes, the following timing changes will also take place on the NCEP Web services:
  • These files will be up to 80 minutes early:
    • gfs.tCCz.goessimpgrb2.1p00.fFFF
    • gfs.tCCz.goessimpgrb2fFFF.grd221
  • These files will be up to 15 minutes early:
    • gdas.tCCz.pgrb2.0p25.fFFF
    • gdas.tCCz.pgrb2.1p00.fFFF
    • memMMM/gdas.tCCz.sfcfFFF.nemsio for some members
    • gdas.tCCz.atmfFFF.nemsio
    • gdas.tCCz.sfcfFFF.nemsio
    • gdas.tCCz.sfluxgrbfFFF.grib2

10) Changes to NOAAPORT/SBN

• The 20km CONUS grid will be changed to use Grid-relative winds to interpolate (U and V) winds for map projection Lambert-conformal. The resolution and component flags will be changed from 48 to 56, and the latitude of the South Pole will be changed from 0 to 90 degree south (-90.000) in Grid Definition Template section (PDT 3.30).
• Additional variables will be created for vertical velocity (DZDT) and continuous precipitation (e.g., APCP, ACPCP). The WMO headers will be the same respectively, but will have different Product Definition Template (PDT) values.
• NCEP plans to remove the legacy variables (VVEL and 6 hourly accumulated precipitation, e.g, APCP, ACPCP) as early as the 2021 upgrade. NCEP is providing an overlap period for users to migrate to the new variables with the GFS v15 implementation.
• In 2014, NCEP added higher resolution grids to NOAAPORT to replace the legacy lower resolution. Please see this notice for WMO information on the new grids. As advertised, the following products will now be removed from NOAAPORT/SBN:

  Grid	Resolution	Area	Map Projection
  #199	2.5 km	Guam	Mercator
  #225	80 km	Hawaii	Mercator
  #160	47 km	Alaska	Polar Stereographic
  #161	0.5 km	Puerto Rico	Lat/Lon
  #213	95 km	Alaska/td>	Polar Stereographic
  #254	40 km	Pacific/td>	Mercator

• The WMO headers for grid 160, 161, 213, 225 and 254 are listed here.
• Users of grid 199 (Guam) output are encouraged to use HiresW Guam products as a replacement available on the NCEP Website under "hiresw." A full list of grid 199 WMO headers being removed can be found here.

For questions regarding these changes, please contact:

Vijay Tallapragada
NCEP/Global Climate and Weather Modeling Branch
College Park, MD
301-683-3672
Vijay.Tallapragada@noaa.gov

For questions regarding the data flow aspects, please contact:

Carissa Klemmer
NCEP/NCO Dataflow Team Lead
College Park, MD
301-683-0567
ncep.list.pmb-dataflow@noaa.gov

NWS National Technical Implementation Notices are online at:

http://www.weather.gov/om/notif.htm

Effective on or about Tuesday June 27, 2017, beginning with the 1200 Coordinated Universal Time (UTC) run, the National Centers for Environmental Prediction (NCEP) will upgrade the GFS Analysis and Forecast System as follows:
 

• Changes to the model components
• Changes to the data assimilation and tropical storm relocation components
• Changes to the post-processing
• Changes to output products

1) Changes to the Global Forecast System Global Spectral Model (GSM) components
 

• Implement GSM source code in NOAA Environmental Modeling System (NEMS) framework
• Upgrade to asynchronous quilting for scalable and efficient write component in NEMS GSM, and replace spectral history file output (sigma files) with new nemsio binary files on model native grid. Documentation of nemsio format including data structure, interface, how to open, read, write, and MPI I/O support are at https://www.emc.ncep.noaa.gov/NEMS/nemsio.php and nemsio library at https://www.nco.ncep.noaa.gov/pmb/codes/nwprod/lib/nemsio
• Implement Near Surface Sea Temperature (NSST) to replace Real-Time Global SST (RTGSST) to provide more realistic ocean boundary conditions
• Upgrade deep & shallow convection schemes with scale- and aerosol-aware features along with convective cloudiness enhancement
• Modify Rayleigh damping to improve temperature and wind forecasts in the upper stratosphere
• Upgrade the land surface model to increase ground heat flux under deep snow; and unify snow cover fraction and snow albedo
• Use new high-resolution MODIS-based snow-free albedo, maximum snow albedo, soil type and vegetation type
• Upgrade surface layer parameterization scheme to modify the roughness-length formulation and introduce a stability parameter constraint in the Monin-Obukov similarity theory to prevent the land-atmosphere system from decoupling.

2) Changes to the Global Data Assimilation System (GDAS) and Tropical Storm Relocation:
 

• Implement Near Sea-Surface Temperature (NSST) Analysis
• Implement CrIS full resolution data assimilation capability
• Implement readiness for new Geostationary Operational Environmental Satellite (GOES-16), Joint Polar Satellite System (JPSS-2) and COSMIC-2 (Constellation Observing System for Meteorology, Ionosphere and Climate) data assimilation capability
• Extend Regional Advanced Television Infrared Observation Satellite (TIROS) Operational Vertical Sounder (ATOVS) Retransmission Services (RARS) and Direct Broadcast Network (DBNet) capability
• Implement bug fix to cloud water increment in Gridpoint Statistical Interpolation (GSI)
• Upgrade land surface type specification in Community Radiative Transfer Model (CRTM)
• Update data monitoring for Megha-tropiques Sounder for Probing Vertical Profiles of Humidity (SAPHIR) and Global Precipitation Measurement (GPM) Microwave Imager (GMI) radiances.
• Assimilate Visible Infrared Imaging Radiometer Suite (VIIRS) Atmospheric Motion Vectors (AMVs) and implement log-normal wind quality control for AMVs
• Assimilate Geostationary Operational Environmental Satellite system (GOES) clear-air water vapor winds
• Assimilate additional global navigation satellite system (GNSS) Radio Occultation (RO) observations.
• Modify pressure and hybrid coordinates transformation during the storm relocation.
• Change relocation of the vorticity and divergence fields to the relocation of u,v wind components
• Remove bogus Tropical Storm/Hurricane data for use in Data Assimilation.
• Assimilate Global Hawk dropsonde data when available
• Upgrade data assimilation monitoring package

3) Changes to the post-processing
 

• Upgrade Post-Processing software to use new nemsio model output
• Implement continuity equation to derive omega on grid space for new nems model output only
• Modify interpolation procedure for all categorical fields including land mask, icing severity and precipitation types products to use nearest neighbor interpolation;
• Generate hourly GFS Flux files directly by the post processor instead of GFS model
• Visibility and second land mask are being added to pgrb2 files for all resolutions.
• 2p5 degree resolution pgrb files will no longer be available on the public servers.
• Remove category rain and correct Grib2 IDs for soil temperature and total column cloud fraction in GFS flux files.
• Time label for SUNSD in GFS Flux files will be changed to instantaneous to be consistent with time label in GFS pressure Grib files.
• The packing for GFS Flux files have been changed to complex packing to be consistent with packing method of GFS pressure Grib files.
• Change interpolation method for CTP (In-Cloud Turbulence Potential) and CB cover (Horizontal Extent of Cumulonimbus) from 'linear' to 'nearest neighbor' to avoid averaging their own specific negative value with normal values when doing grid conversion

4) Changes to output products

With this upgrade the following changes will be noted on the NWS web services:

• ftp://ftp.ncep.noaa.gov/pub/data/nccf/com/gfs/prod
• https://www.ftp.ncep.noaa.gov/data/nccf/com/gfs/prod
• https://nomads.ncep.noaa.gov
• ftp://tgftp.nws.noaa.gov/SL.us008001/ST.opnl/
• https://weather.noaa.gov/pub/SL.us008001/ST.opnl/

 

• Increase the frequency of station time-series BUFR data every hour to 120 hours, and then every 3 hours to 240 hours
• Modify the list of stations from 1919 to 2021 on NOAAPORT and NCEP servers, for which BUFR data are generated for the GFS. The changes will also modify the lists of stations in the GFS BUFR sounding collectives disseminated on NOAAPORT. For the full list please reference this page: https://docs.google.com/document/d/15exFN-0W36cS4rNULALyh_qTJcl8hBBTBZozdRxM_0s/edit#
• Correct a few errors in the original station list. Land/water designations were added for those stations that do not have the designations
• Change station bufr sound file name from bufr3.STN_ID.YYYYMMDDHH to bufr.STN_ID.YYYYMMDDHH
• Replace copygb2 by WGRIB2 in downstream products and change the basic angle of the initial production domain from 0 to -1 for all 0.25 degree; 0.5 degree; and 1.0 degree grib2 output; AWIPS 20km Puerto Rico grid;
• Replace copygb2 by WGRIB2 in all AWIPS products and correct the resolution and component flag from 8 to 48 for AWIPS 160 grid; AWIPS 20km CONUS grid; AWIPS 20km AK grid; AWIPS 20km Puerto Rico grid and AWIPS Grid 213 (National - CONUS - Double Resolution Polar Stereographic 95km)
• Add 925 mb for fields: HGT, TMP, VVEL, RH and U and V windows components to AWIPS Global Lat/Lon (1.0 deg) grid
• Replace copygb2 by WGRIB2 in all GEMPAK grids and correct the resolution and component flag from 8 to 48 and basic angle of the initial production domain from 0 to -1

List of file name changes:

All files that had filename prefix "gdas1" will be renamed with filename prefix "gdas" (unless they are in the list of files to be discontinued).
 

Current Production File Name

New Production File Name

gfs.tCCz.sgesprep gfs.tCCz.sgmHprep gfs.tCCz.sgpHprep gfs.tCCz.sanl gfs.tCCz.sfcanl gfs.tCCz.sfHH gfs.tCCz.bfHH gdas1.tCCz.sanl gdas1.tCCz.sfcanl gdas1.tCCz.abias gdas1.tCCz.abias_pc gdas1.tCCz.abias_air gdas1.tCCz.radstat gdas1.tCCz.sfHH gdas1.tCCz.bfHH gdas1.tCCz.pgrb2.1p00.anl gdas1.tCCz.pgrb2.1p00.anl.idx gdas1.tCCz.pgrb2.0p25.anl gdas1.tCCz.pgrb2.0p25.anl.idx gdas1.tCCz.pgrb2.1p00.fHHH gdas1.tCCz.pgrb2.1p00.fHHH.idx gdas1.tCCz.pgrb2.0p25.fHHH gdas1.tCCz.pgrb2.0p25.fHHH.idx gdas1.tCCz.sfluxgrbfHH.grib2 sfcanl_YYYYMMDDCC_ensmean sfcanl_YYYYMMDDCC_memXXX sfg_YYYYMMDDCC_fhrHH_memXXX bfg_YYYYMMDDCC_fhrHH_memXXX sfg_YYYYMMDDCC_fhrHH_ensmean bfg_YYYYMMDDCC_fhrHH_ensmean sfg_YYYYMMDDCC_fhrHHs_memXXX

gfs.tCCz.atmges.nemsio gfs.tCCz.atmgmH.nemsio gfs.tCCz.atmgpH.nemsio gfs.tCCz.atmanl.nemsio gfs.tCCz.sfcanl.nemsio gfs.tCCz.atmfHHH.nemsio gfs.tCCz.sfcfHHH.nemsio gdas.tCCz.atmanl.nemsio gdas.tCCz.sfcanl.nemsio gdas.tCCz.abias gdas.tCCz.abias_pc gdas.tCCz.abias_air gdas.tCCz.radstat gdas.tCCz.atmfHHH.nemsio gdas.tCCz.sfcfHHH.nemsio gdas.tCCz.pgrb2.1p00.anl gdas.tCCz.pgrb2.1p00.anl.idx gdas.tCCz.pgrb2.0p25.anl gdas.tCCz.pgrb2.0p25.anl.idx gdas.tCCz.pgrb2.1p00.fHHH gdas.tCCz.pgrb2.1p00.fHHH.idx gdas.tCCz.pgrb2.0p25.fHHH gdas.tCCz.pgrb2.0p25.fHHH.idx gdas.tCCz.sfluxgrbfHH.grib2 gdas.tCCz.sfcanl.ensmean.nemsio gdas.tCCz.sfcanl.memXXX.nemsio gdas.tCCz.atmfHHH.memXXX.nemsio gdas.tCCz.sfcfHHH.memXXX.nemsio gdas.tCCz.atmfHHH.ensmean.nemsio gdas.tCCz.sfcfHHH.ensmean.nemsio gdas.tCCz.atmfHHHs.memXXX.nemsio

List of files removed:

The following surface analysis, bufr dump and prepbufr files will no longer be generated:

• gdas1.tCCz.*.tm00.bufr_d.unblok
• gdas1.tCCz.*.tm00.bufr_d.unblok.nr
• gfs.tCCz.prepbufr.unblok
• gfs.tCCz.prepbufr.unblok.nr
• gfs.tCCz.pgrb2.2p50.fHHH (where HHH is 000 to 384)
• gdas1.tCCz.prepbufr.unblok
• gdas1.tCCz.prepbufr.unblok.nr
• sfcanl_CDATE_ensmean
• sfcanl_CDATE_mem001~080

Files with the same content will continue to be available without the "unblok" filename qualifier (and with the change in prefix for gdas files). Eg, file gdas1.t00z.adpupa.tm00.bufr_d.unblok will be available as gdas.t00z.adpupa.tm00.bufr_d and file gfs.t00z.prepbufr.unblok.nr will be available as gfs.t00z.prepbufr.nr. There is one exception to the pattern in that gdas1.tCCz.sfcshp.tm00.bufr_d.unblok will be available as gdas.tCCz.sfcshp.tm00.bufr_d.nr.

NCEP urges all users to ensure their decoders can handle changes in content order, changes in the scaling factor component within the product definition section (PDS) of the GRIB files, and volume changes. These elements may change with future NCEP model implementations. NCEP will make every attempt to alert users to these changes before implementation.

For questions regarding these changes, please contact:

Vijay Tallapragada
NCEP/Global Climate and Weather Modeling Branch
College Park, MD
301-683-3672
Vijay.Tallapragada@noaa.gov

For questions regarding the data flow aspects, please contact:

Carissa Klemmer
NCEP/NCO Dataflow Team Lead
College Park, MD
301-683-0567
ncep.list.pmb-dataflow@noaa.gov

NWS National Technical Implementation Notices are online at:

http://www.weather.gov/om/notif.htm
 

Effective on or about Tuesday May 11, 2016, beginning with the 1200 Coordinated Universal Time (UTC) run, the National Centers for Environmental Prediction (NCEP) will upgrade the GFS Analysis and Forecast System as follows:   - Changes to the data assimilation components
  - Changes to the model components
  - Addition of hourly gridded output through 120 hours
  - Addition of five layers in the upper stratosphere in gridded output
  - Addition of new product fields
  - Product removals

Read full TIN: http://www.nws.noaa.gov/os/notification/tin16-11gfs_gdasaaa.htm

1) Changes to the Global Data Assimilation System (GDAS):

- Upgrade the 3D Hybrid Ensemble-Variational to 4D Hybrid Ensemble-Variational Data Assimilation System 4D increments are constructed by figuring out best combination of 4D ensemble perturbations. The weights for ensemble members are kept constant throughout the assimilation window. The 4D-Hybrid uses 50 outer and 150 inner iterations with variational quality control turned on after 25 iterations. Tangent Linear Normal Mode Constraint (TLNMC) and Digital Filter Initialization (DFI) are used in the ensembles while additive error inflation is removed. Ozone cross covariances are in the 4D-Hybrid.  Localization is recued to 50 percent in the troposphere and the weights for static and ensemble are kept at 12.5 percent and 87.5 percent respectively.
- Assimilate all sky Advanced Microwave Sounding Unit (AMSU-A) Radiances
- Assimilate Advanced Very High Resolution Radiometer (AVHRR) winds and monitor Visible Infrared Imaging Radiometer Suite (VIIRS) winds
- Implement Geostationary Operational Environmental Satellites R-series (GOES-R) data readability
- Update Community Radiative Transfer Model (CRTM) to v2.2.1 with bug fixes in wind direction, use of FAST Microwave Emissivity Models (FASTEM-6 and FASTEM-X) reflection correction for cloudy situations
- Improve bias correction for aircraft observations
- Modify relocation and storm tracking to allow hourly tropical cyclone relocation
- Modify thinning/weight in time for Atmospheric Motion Vectors (AMVs) and radiances
- Upgrade data assimilation monitoring package

2) Model changes to the GFS Global Spectral Model and post-processing software:

- Correct the land surface characteristics for grassland and cropland categories to reduce summertime warm and dry biases over Great Plains
- Upgrade convective gravity wave drag
- Upgrade tracer adjustment in the semi-Lagrangian dynamic core
- Upgrade the NCEP Unified Post Processing (UPP) software to v7.0
- Implement Global Current Icing Potential analysis (G-CIP) products

3) Output product changes

All operational products below can be found on any of following NCEP or NWS servers:

ftp://ftp.ncep.noaa.gov/pub/data/nccf/com/gfs/prod
http://www.ftp.ncep.noaa.gov/data/nccf/com/gfs/prod
http://nomads.ncep.noaa.gov
ftp://tgftp.nws.noaa.gov/SL.us008001/ST.opnl/
http://weather.noaa.gov/pub/SL.us008001/ST.opnl/

- Add new Global Forecast Icing Severity (G-FIS) icing severity parameter (ICSEV Icing Severity)

  gfs.tCCs.pgrb2.0p25.fFFF
  gfs.tCCs.pgrb2.0p50.fFFF
  gfs.tCCs.pgrb2.1p00.fFFF

    Where CC is 00, 06, 12, 18
    Where FFF is 000 to 384

- Improve Global Forecast Icing Potential (ICIP) products

  WAFS_blended_YYYYMMDDCCfFF.grib2

    Where FF is 06 to 36

- Include hourly forecasts out to 120 hr

  gfs.tCCz.pgrb2.0p25.fFFF
  gfs.tCCz.pgrb2b.0p25.fFFF

    Where FFF is 000, 001, 002, 003, 004...120

- Add grib filter and GDS/OpenDAP availabilty of the 2.5 deg hourly forecasts in NOMADS.

- filter_gfs_0p25_1hr.pl (grib filter link)
- gfs_0p25_1hr (OpenDAP-alt link)

At this time data will not be available for testing until it goes into operations.

- Add five more vertical levels (7, 5, 3, 2, and 1 hPa) for the variables geopotential height (HGT), temperature (TMP), relative humidity (RH), U- and V- components of wind (UGRD and VGRD) and ozone mixing ratio (O3MR)

  gfs.tCCz.pgrb2.0p25.fFFF, gfs.tCCz.pgrb2b.0p25.fFFF
  gfs.tCCz.pgrb2.0p50.fFFF, gfs.tCCz.pgrb2b.0p50.fFFF
  gfs.tCCz.pgrb2.1p00.fFFF, gfs.tCCz.pgrb2b.1p00.fFFF
  gfs.tCCz.pgrb2.2p50.fFFF   

    Where FFF is forecast hours from 000 to 384

- Replace 775 hPa state variables with 750 hPa in the GFS WAFS grids 37-44 for UGRD, VGRD, TMP, RH, HGT

  On NCEP Servers:

  wafsgfs_L_tCCz_intdskFFF.grib2
  wafsgfs_P_tCCz_intdskFFF.grib2

  On NWS Servers:

  fh.0FFF_tl.press_ar.octant(ijklmno)   

    Where FFF is 000-120

- Add GDAS ABIAS air BUFR file

  gdas1.tCCz.abias_air

- Modify the list of stations on NOAAPORT and NCEP servers, for which BUFR data are generated for the GFS.  The changes will also modify the lists of stations in the GFS BUFR sounding collectives disseminated on NOAAPORT. For the full list please reference this page:

http://www.nco.ncep.noaa.gov/pmb/changes/gfs_upgrade_2016.shtml

The following changes to NOAAPORT are detailed below with the following WMO headers for each grid:

http://www.nco.ncep.noaa.gov/pmb/changes/gfs_20kmAWIPS_grids.shtml

- Alaska region grid 217 (20km) has been modified to expand latitude from 30N to 35N and longitude from 173W to 170W.

- The Maximum and Minimum Temperatures (TMAX, TMIN) Product Definition Template 4.8 will correct a mistake in the second fixed surface from "255 0 2" to "255 0 0" for the following grids:

  Alaska region 20km
  Pacific region 20km
  Puerto Rico 0.25deg
  CONUS 20km

- The Water Equivalent of Accumulated Snow Depth (WEASD) WMO headers were incorrectly labeled for forecast hours 186, 198, 210, 222 and 234. The following changes will be applied to each grid below:

  CONUS 20km: LSRU98 -> ZSNZ98
  Alaska 20km: LSRU98 -> ZSBZ98
  Pacific Region 20km: LSRU98 -> ZSEZ98
  Puerto Rico 0.25deg: LSRU98 -> ZSFZ98

- The Alaska region grid 217 (20km) had some incorrectly labeled forecast hours in the grid identifier WMO header. This will be addressed so all Alaska WMO products have A1 = B

- Addition of GRIB2 20 km gridded product over Pacific Region (Mercator) to NOAAPORT

  Runs 4 times per day at 00z, 06z, 12z and 18z

  WMO headers will be as follows:

  T1 = Y for forecast hours: 00, 06, 12, 15, 18, 24, 30, 36, 42, 48, 60, 72, 84, 96, 108,120, 132, 144, 156, 168, 180, 192, 204, 216, 228, 240

  T1 = Z for forecast hours: 03, 09, 15, 21, 27, 33, 39, 45, 51, 54, 57, 63, 66, 69, 75, 78, 81, 90, 102, 114, 126, 138, 150, 162, 174, 186, 198, 210, 222, 234

  T2 specifies the parameters as follows:

     T = Temperature, TMIN, TMAX; H = Height;
     5-wave geopotential height; O = Vertical velocity;
     R = Relative humidity; C = Absolute vorticity;
     U = u-component of wind; V = v-component of wind;
     P = Pressure; Pressure reduce to Mean Sea level;
     B = Vertical speed shear; E = Total precipitation;
     G = Convective precipitation; Q = Best Lifted Index;
     W = Convective Available Potential Energy;
     Y = Convective Inhibition; X = Surface Lifted Index;
     F = Precipitable Water; M = Precipitable Water;
     S = Water Equivalent of Accumulated Snow Depth;

  A1 = E* Grid 20 km, Pacific Region

  *Was incorrectly labeled "F" in the previous advertised TIN 14-54

  A2 specifies the forecast hours as follows:

     A=00; B=06; C=12; D=18; E=24; F=30; G=36; H=42;
     I=48; J=60; K=72; L=84; M=96; N=108; O=120;
     P=132; Q=144; R=156; S=168; T=180; U=192; V=204;
     W=216; X=228; Y=240 (Note: T1 is Y)

     B=03; E=09; H=15; K=21; L=27; O=33; P=39; Q=45;
     R=51; M=54; S=57; Z=63; N=66; Z=69; Z=75; T=78;
     Z=81; U=90; V=102; W=114;
     Z=126; 138; 150; 162; 174; 186; 198; 210; 222;
     234 (Note: T1 is Z)

    ii specifies level as follows:

     99=1000mb; 93=975mb; 95=950mb; 92=925mb; 90=900mb;
     91=875 mb; 85=850mb; 82=825mb; 80=800mb; 77=775mb;
     75=750mb; 72=725mb; 70=700mb; 67=675 mb; 65=650mb;
     62=625 mb; 60=600mb; 57=575mb; 55=550mb; 52=525mb;
     50=500mb; 45=450mb;40=400mb; 35=350mb; 30=300mb;
     25=250mb; 20=200mb; 15=150mb; 10=100mb;
     73=High, Mid, Low cloud bottom level; 86=Boundary Layer;
     89=Reduced to Sea Level; 94=Level of the 0 deg. C isotherm;
     96=Maximum wind level;
     97=Level of the Tropopause, potential vorticity surface;
     98=Surface of Earth; 00=Entire Atmosphere

  See the following link for a full list of WMO headers:

    http://www.nco.ncep.noaa.gov/pmb/changes/gfs_pac_wmo.txt

4) Output product removals

NCEP has been working to remove low resolution legacy products in lieu of higher resolution grids. Last year NCEP added new higher resolution grids to NOAAPORT in preparation for removing the legacy grids. Due to the positive responses received from the NCEP Public Information Statement 16-04, Removal of Legacy Global Forecast System (GFS) Gridded Output, the following products will be removed with this upgrade:

- Remove the GFS grid 212, 40km Regional CONUS from NOAAPORT

  WMO Headers:

http://www.nco.ncep.noaa.gov/pmb/changes/gfs_AWIPS_grids.shtml

To find the replacement products please reference this TIN:

http://www.nws.noaa.gov/os/notification/tin14-54gfs_noaaport.htm

- Removal Vessel Sea Ice and Fog on grid 232, 1 deg Northern

Hemisphere from NOAAPORT

  WMO Headers:

http://www.nco.ncep.noaa.gov/pmb/changes/omb_AWIPS_grids.shtml

- Removal of 1.25 deg GRIB1 GFS WAFS products from the NWS

http/ftp server:

weather.noaa.gov/pub/SL.us008001/ST.opnl/MT.gfs_CY.CYCLE/RD.YYYY

MMDD/PT.grid_DF.gr1/fh.FFF_tl.press_ar.octant[ijklmnop]

ftp://tgftp.nws.noaa.gov/SL.us008001/ST.opnl/MT.gfs_CY.CYCLE/RD.

YYYYMMDD/PT.grid_DF.gr1/fh.FFF_tl.press_ar.octant[ijklmnop]

  where CYCLE is 00, 06, 12, 18
  where YYYYMMDD is Year, Month, Day
  where FFF is forecast hour from 000-120
 

To find the replacement product please reference this TIN:

http://www.nws.noaa.gov/os/notification/pns16-04gfs_removal.htm

- Removal of 1.25 deg GRIB1 GFS WAFS products from the NCEP

http/ftp server:

http://nomads.ncep.noaa.gov/pub/data/nccf/pcom/gfs/xtrn.wfsgfs*
ftp://ftp.ncep.noaa.gov/pub/data/nccf/pcom/gfs/xtrn.wfsgfs*

To find the replacement product please reference this TIN:

http://www.nws.noaa.gov/os/notification/pns16-04gfs_removal.htm

5) Parallel data available

Starting in April 1, 2016 all parallel data sets will be available on the following servers:

http://para.nomads.ncep.noaa.gov/pub/data/nccf/com/gfs/para

For more information on this GFS upgrade, please see EMC real-time and retrospective parallels and verification pages:

http://www.emc.ncep.noaa.gov/gmb/noor/4dGFS/synergy%20announcementjan08.htm

NCEP urges all users to ensure their decoders can handle changes in content order, changes in the scaling factor component within the product definition section (PDS) of the GRIB files, and volume changes. These elements may change with future NCEP model implementations. NCEP will make every attempt to alert users to these changes before implementation.

For questions regarding these changes, please contact:

     Vijay Tallapragada
     NCEP/Global Climate and Weather Modeling Branch
     College Park, MD

     301-683-3672

     Vijay.Tallapragada@noaa.gov

For questions regarding the data flow aspects of these data

sets, please contact:

     Carissa Klemmer
     NCEP/NCO Dataflow Team Lead
     College Park, MD

     301-683-0567

     ncep.list.pmb-dataflow@noaa.gov

NWS National Technical Implementation Notices are online at:

   http://www.nws.noaa.gov/os/notif.htm