NOUS41 KWBC 211350 AAA



Technical Implementation Notice 16-11 Amended

National Weather Service Headquarters Washington DC

950 AM EDT Thu Apr 21 2016


To:        Subscribers:

           -NOAA Weather Wire Service

           -Emergency Managers Weather Information Network


           Other NWS Partners, Users and Employees


From:      Timothy McClung

           Chief Operating Officer

           NWS Office of Science and Technology Integration


Subject:   Amended Global Forecast Systems (GFS) Upgrade:

           Effective May 11, 2016


Amended to add the Pacific Region 20km grid to NOAAPORT and the

hourly 0.25 deg in NOMADS


Effective on or about Wednesday 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


  - Addition of new product fields

  - Product removals


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 the best

combination of 4D ensemble perturbations. The weights for

ensemble members are kept constant throughout the assimilation

window. 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 reduced to 50% in the troposphere and

the weights for static and ensemble are kept at 12.5% and 87.5%


- Assimilate all sky Advanced Microwave Sounding Unit (AMSU-A)


- 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 read ability

- 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


- Implement Global Current Icing Potential analysis (G-CIP)



3) Output product changes

All operational products below can be found on any of following

NCEP or NWS servers:



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

parameter (ICSEV Icing Severity)




    Where CC is 00, 06, 12 and 18

    Where FFF is 000 to 384


- Improve Global Forecast Icing Potential (ICIP) products


    Where FF is 06 to 36


- Include hourly forecasts out to 120 hr



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


- Add grib filter and GDS/OpenDAP availability of the 0.25 deg

hourly forecasts in NOMADS.

  - (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


    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:



  On NWS Servers:


    Where FFF is 000-120


- Addition of GDAS ABIAS air BUFR file



- 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:


The following changes to NOAAPORT are detailed below with the

following WMO headers for each grid:


- 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


  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



  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=975 mb; 95=950 mb; 92=925 mb; 90=900mb;

     91=875 mb; 85=850mb; 82=825 mb; 80=800 mb; 77=775 mb;

     75=750mb; 72=725mb; 70=700mb; 67=675 mb; 65=650 mb;

     62=625 mb; 60=600mb; 57=575 mb; 55=550mb; 52=525 mb;

     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:


4) Output product removals

NCEP has been working to remove low resolution legacy products

and replace them with 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:


To find the replacement products please reference this TIN:


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

Hemisphere from NOAAPORT

  WMO Headers:


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

http/ftp server:



  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:


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

http/ftp server:**


To find the replacement product please reference this TIN:


5) Parallel data available

Starting in April 1, 2016 all parallel data sets will be

available on the following servers:


For more information on this GFS upgrade, please see EMC real-

time and retrospective parallels and verification pages:


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



For questions regarding the data flow aspects of these data sets, please contact:


     Carissa Klemmer

     NCEP/NCO Dataflow Team Lead

     College Park, MD



NWS National Technical Implementation Notices are online at: