Gateway File Services

Model-Specific Product Files

(NOT ALL FILES DESCRIBED ARE CURRENTLY AVAILABLE)

Introduction

The U.S. National Weather Service provides anonymous FTP access to files containing computer generated analysis and forecast MODEL products. They are available on the server in WMO bulletin form, used for GTS and Family of Services standard transmission, or as individual files of model products. Most files are in form of WMO GRIB or BUFR standard coded format. Some files are in text format and some are in T4 facsimile format with enveloped TIFF and display formats such as "gif".   The format of the directories and file names follow the NWS standard on this OSO WebSite server. The bases to the directory and filename are described in the NWS standard document called the File and Directory Name Standards developed as a draft in OFCM.   The data is available on the server tgftp.nws.noaa.gov via anonymous FTP. The forecast or analysis "area of coverage" and "specific levels of the atmosphere" are not key elements to the selectability of the product files on this server. This server provides these products for retrieval purposes only. The users must further store these files for interactive use. This is a communications providing service and no attempt to archive data is made.

Information Available

The following computer generated products are available on the server.  The set of information available includes all unrestricted data received at the NWS Telecommunication Gateway from the National Centers for Environmental Prediction (NCEP) as well as other National and International sources. It does not include additional data as defined by WMO Resolution 40. That information is provided elsewhere.

Category of Products

Category I (Binary)

Category II (Facsimile & Pictorial)

Category III (Text)

Category IV (Binary-Specialized)

Category I

Products available in the WMO GRIB Code, BUFR code, or OFCM Red Book Format

Currently Available Products by Model

• Global Aviation Model
• Eta Model
• Global Data Assimilation System (Final) Model
• Medium Range Forecast Model
• Nested Grid Model
• Regional Spectral Model
• Rapid Update Cycle Model
• NOAA Wave Watch III Model
• Global Ensembles
• Regional Ensembles
• Climate Model

Directory and File Name Structure

Server File Populating Details

UPDATE PROCESS

Data is updated on the FTP server as received with the latest information added within the subdirectory as received from NWS communications sources. The subdirectory ST.ssss separates experimental data from operational data. The subdirectory MT.mmm(mm)_CY.hh will provide selectibility between generating forecast models (i.e. AVN, ETA, MRF, etc.) and their cycle run times. Files within each directory tree have the format which will destinguish the analysis or forecast field.

Directory & Filename - An Example

SL.008001/ST.opnl/MT.ruc_CY.06/RD.20000622/PT.grid_DF.gr1/fh.0003x_tl.press

where;
The directory tree is: SL.008001/ST.opnl/MT.ruc_CY.06/RD.20000622/PT.grid_DF.gr1/
The filename is: fh.0003x_tl.press

NOTE:In some cases the gr.gggggggg information element field is also included in the file name to specify the "grid" used when the file contain does not have a WMO heading on the product.

This sample tree is for the 06Z cycle-based RUC model product for pressure fields for the 3rd hour forecast. This tree defines files without the WMO envelope [no WMO Abbreviated Headings and ending etx]. This set of files would be for the June 22, 2000 0600Z cycle run.

To better understand the importance of this directory level here are some of the definitions that the MT.mmm(mm)_CY.hh subdirectory can currently equate to:

NOTE: F3F3F3 = from WMO Manual 306 "Code Table C0" for designation of modelling Center. FFF = 007 - US NWS-NCEP(NMC); FFF = 034 - JMA-Tokyo; FFF = 074 - UK Met Office

Also, the data format definition in a directory level will distinguish between files which contain WMO bulletins and files which contain products in the code form, but without the WMO bulletin envelope. The WMO bulletin contains the T1T2 A1A2ii CCCC heading and ends with the ETX [hex 03], where as, other files will contain products starting with the word GRIB or BUFR and end with 7777 both in ASCII characters. The DF.ff(f) Key field will provide file content form as defined below.

REMOVAL LEVEL

The subdirectories and files are removed from the server when the next model of that cycle begins. Removal of files start with the subdirectory RD.yyyymmdd. This scheme provides unique file availability on the server for the previous 24 hours of computer generated production for the source model generating center. The subdirectory layer that defines the "Data Format" permits selection of files either in WMO bulletin form or GRIB products in file form only. Some NCEP model products are not exchanged on the GTS; therefore, the WMO Abbreviated Heading, which is a communications product identifier, does not appear in some GRIB files.

Data files are written only when data of that reference date are available. There will be brief periods of time when subdirectories and files will not be defined on the server, as the new files will only be written after timed prior cycle removal, pending on a successful cycle run by the modeling center.

Climate Model

The climate data files have a longer time between removals from our servers, therefore, they are decribed here separately from the other model data directory and file name structures above. The files will contain hindcast and forcast averages, means, ensembles per year, multiple months in periods of coverage, and are generated in monthly increments.

Directory and File Name Structure

The climate files will be removed after two months by generation date DD.yyymm (the data date indicator for the infomation).

Directory & Filename - An Example

SL.us008001/ST.opnl/MT.clim_MR.hind/DD.200112_PA.ensmeans/PT.grid_DF.gr1/rd.200111_pa.member01_tl.press

where;

The directory tree is:
SL.us008001/ - NWS Telecommunication Gateway server
ST.opnl/ - operational data
MT.clim_MR.hind/ - Model source is the climate model producing the hindcast
DD.200111_PA.ensmeans/ - data date coverage with a parameter for the ensemble means
PT.grid_DF.gr1/ - product type is grid in GRIB adition 1

The filename is:
rd.200111_pa.member01_tl.press - the year and month of coverage for the pressure field, and the iteration of the base data used.

NOTE: the use of the "Directory & File Name Standard" uses the year and month where dates are used but not the day of the month as this has no meaning for climate products.

Category II

Products in Facsimile or Pictorial Format

The facsimile analysis and forecast graphical products are described in html pages at Weather Charts on the Web for individual retrieval. The U.S. National Weather Service provides anonymous FTP at ftp://weather.noaa.gov/fax/ for individual retrieval in either TIFF enveloped files or in some cases as GIF files. The original T-4 WMO agreed upon file code format products are available on the server ptgftp.nws.noaa.gov via anonymous FTP.

Currently Available Products by format (models & sources vary)

• Facsimile - TIFF viewable format
• Facsimile - FAX T-4 1D decodable format
• pictorial - GIF viewable format
• pictorial - JPG viewable format
• graphical - RGB Redbook decodable format (OFCM S-2 code based)

See Directory and File Naming Standards for information about directory and file name formats and definable product types.

Directory and File Name Structure for Facsimile & graphical Products

NOTE: The facsimile charts are only retreivable as one separate individual product per file. Also, the normal "KEY" in the filename field does not appear (see standard).

Directory & Filename - An Example

SL.008001/ST.opnl/MT.avnx_CY.00/RD.20000622/PT.graf_DF.f1/pwab85.fax

NOTE: Extension can either be FAX, GIF, or JPG depending on product format generation for display. Normally the FAX extension product (the originating CCITT T-4 code format) is not a standard display format, therefore, for display this form is enveloped in TIF.

REMOVAL LEVEL

The subdirectories and files are removed from the server when the next model of that cycle begins. Removal of files start with the subdirectory RD.yyyymmdd. This scheme provides unique file availability on the server for the previous 24 hours of computer generated production for the source model generating center. The subdirectory layer that defines the "Data Format" permits selection of files either in WMO bulletin form or GRIB products in file form only. Some NCEP model products are not exchanged on the GTS; therefore, the WMO Abbreviated Heading, which is a communications product identifier, does not appear in some GRIB files.

Data files are written only when data of that reference date are available. There will be brief periods of time when subdirectories and files will not be defined on the server, as the new files will only be written after timed prior cycle removal, pending on a successful cycle run by the modeling center.

Further questions or comments concerning data in SL.us008001 path may be directed to NWS.ISG@noaa.gov.

Category III

Text Products based upon Computer Models

The NCEP Central Operations produces products in ASCII text tabular format for areas and site locations. These forecasts come from various models executed at the NCEP center(s). Their availability is based upon generation schedules set by NCEP.

Currently available products are:

• FEUS21-26 KWNO - (MRF model) Extended guidance
• FOXS48 KWBC - (MRF model) Based Objective Guidance
• FOUS12 KWNO - (MRF model) MAX/MIN Temp POP Guidance [AVN & MRF]
• FOUS14 Kxxx - (NGM model) wind/cloud guidance [Kxxx = site ID]
• FOUS40-47 KWNO - (ETA model) freezing level/relative humidity
• FOUS50-57 KWNO - (NGM model) trajectory forecast
• FOUS60-78 KWNO - (ETA model) relative humidity/temperature guidance

See Directory and File Naming Standards for information about directory and file name formats and definable product types.

Directory and File Name Structure

These products will be filed as received for a period of 24 hrs and written within 15 minutes of Gateway receipt. The sequence numbers will be cyclic values ranging from 01-to- 12 for each receipt of the product as received.

Category IV

Products in Binary Code Format for Specialized Purposes

There are computer generated analysis and forecast products available from various automated centers to address special requirements. The U.S. National Weather Service provides anonymous FTP access to them at ftp://tgftp.nws.noaa.gov/SL.us008001/ for individual retrieval in files by individual product receipt. The variations in product types and formats available at the Gateway by the generating centers do not permit furture definition that provided here on the server for anonymous FTP retrieval.

Currently available GRIB & BUFR products are:

• JSAT98 KKCI - National Convective Weather Forecast [NCWF]
• ZDIA98 KKCI - National Convective Weather Diagnostic [NCWD]
• YAWAi1i2 KKCI - Current Icing Potential - Total Icing Potential
• YAXAi1i2 KKCI - Current Icing Potential - SLD
• YAWa1i1i2 KKCI - Forecast Icing Potential [FIP] (up to 2mb per file) a1 = B C D G J M
• YVWa1i1i2 KKCI - Graphical Turbulence Guidance [GTG] a1 = A D G J M

Directory and File Name Structure for computer generated binary Products

The binary products are only retreivable as one separate individual product per file.

Directory & Filename - An Example

SL.008001/DC.avspt/DS.ncwf/PT.bin_DF.buf/sn.0010.bin

NOTE: Optional extension bin is used in this file name on products generation for computer processing after receipt. This example contains BUFR. If the DF (data format) was GRIB version 1 and the content was gridded fields the subdirectory would be /PT.grid_DF.gr1/.

REMOVAL LEVEL

These files are not removed. The products will be filed as received for a minimum period of 24 hrs and written within 5 minutes of Gateway receipt. The file name sequence numbers sn.xxxx will range cyclic in value from 0001-to-0300 each containing a receipt of the product as received.