1. New tool to ease GFS data download and processing
Juan José A. Figueroa (MARN, El Salvador)
Angelo Pascualetti (DMC, Chile)
Michel Davison (WPC / NOAA, USA)
and
José Gálvez (SRG / WPC / NOAA, USA)
July 29, 2014

2. What was developed?
Software Bundle: Set of Windows programs & installer
They simplify the download of 0.5°-GFS grib data
tiles from the NCEP NOMADS server to a
Windows PC/Laptop
Installer includes the WingriddsV3.2* grid-analysis
software plus macros/scripts developed at the
International Desks for the analysis of model data
*Wingridds: Software for gridded-data analysis in Windows Systems
developed by Jeff Krob.

3. Goal Effort targeted at the needs of Latin America’s
Forecasting community, but tool is useful anywhere
Part of the WPC International Desks Support to
WMO regions III and IV

4. GFS data & Latin America
Thanks to NOAA, Latin America is highly benefited by the availability of GFS model data. These are used primarily for
-Weather Forecasting
-Initialization of regional models
in countries with the capabilities
-Research

5. Download and Analysis Methods
GFS Grib Data are often downloaded from
-the TGFTP Server (most known/used choice)
ftp://tgftp.nws.noaa.gov
Once downloaded, gridded GFS data are often
processed/analyzed using
-WINGRIDDS (Forecasting-Oriented Software for Windows)
-GRADS (Research-Oriented Software for LINUX)
-other software

6. Common Limitations #1 Speed of internet connection Other
Storage Space
Other
Computing Skills to play with the data
-Important to make things easier so more
people manage to obtain, read and analyze
the data instead of just visualizing plots online
-Files can be too large if stored for research

7. GFS Data often used 1. WAFS (Weather Area Forecast System)
2. Global data
•1-degree
•0.5-degree
All available at the tgftp server:
ftp://tgftp.nws.noaa.gov

8. 1.WAFS (Weather Area-Forecast System)
WMO / NOAA / UKMET effort that started during the
mid-90s to support aviation and weather forecasting
Consists of
Global model data interpolated into
1.25-degree grids
WMO=World Meteorological Organization
Mandatory Pressure Levels
Divided for different sectors around the globe
(smaller files instead of large global data files)

9. WAFS Sectors L and P L P 90N 120W 30W EQ 120W 30W 90S
WMO=World Meteorological Organization
120W P
30W
90S

10. 1.WAFS INITIALLY… Winds and temperatures 1.25°-grid, Mandatory Levels
Through 36 hrs, every 3
NOW
Winds, temperatures, Omegas, RH, Precipitation
1.25°-grid, Mandatory Levels
Every 3 hrs through F36h
Every 6 hrs from F42h to F120h
File size: ~369 KB/forecast hour

11. 2.GFS Global Data
Much more completemore information but larger files.
VARIABLES:
Winds, Temperature, Omegas, RH, Precip, Precip Type, Max/Min Temp, Vorticity, Cloud Height, 0 Degree Isotherm, etc,etc.
LEVELS:
Every 50hPa plus some sigma-level data.
HOURS:
Every 3hrs through 192 hrs.
FILE SIZE PER FCST HOUR:
1-degree: ~16.7 MB
0.5-degree: ~51.7 MB

12. 2.GFS Global Data
Horizontal Resolution
1-degree
0.5-degree

13. 2.GFS Global Data Vertical Resolution 50 hPa Every 50hPa Every 25hPa
+ Some sigma (terrain-following) levels

14. Recommended if you have the capability
Dataset Inter-comparison
WAFS
Global 1°
Global 0.5°
File size per hour
51.7 MB
16.7 MB
0.37 MB
-Easy download
-Lengthy download
-Broadband capability
required
Recommended if you have the capability
Resolution
1.25 °
1.0 °
0.5 °
-Resolves meso-
synoptic features
-Resolves only
-Limited vertical
resolution

15. Other Options
What about those who don’t have the high speed capability and would like to download the higher resolution data?

16. NOMADS Data Server http://nomad5.ncep.noaa.gov/ncep_data/index.html

17. NOMADS Data Server Allows you to select the resolution Time increment
Parameters
Create your own sectors

18. Example: Mexico-Caribbean Sector (Tile) Instead of 51.7MB, 9.4MB

19. Advantages
Higher resolution data in smaller files, packaged for your convenience.
Can modify the area to suit your needs and available communication capabilities
Can make it smaller/larger
However, you need to pick your settings by hand and submit them to the NOMADS server
Can this be made automatic?

20. The International Desks Team has developed a software bundle that simplifies the download of these high-resolution sector data, with chance for full automation
YES!
Software Bundle…
Installs Wingridds V3.2 including updated & documented
macros/scripts developed and used at the International
Desks for analysis, forecasting and training.
(2) Contains a set of scripts that allow
•automatic download of 0.5-degree GFS sector data
from the NOMADS server
•automatic conversion of these into Wingridds format

21. Mexico-Caribbean Tile
Two sectors supported in bundle
Mexico-Caribbean Tile
9.4MB vs…
9.4MB
51.7MB Global File in TGFTP (18%)
233MB Global File in NOMADS (4%)
South America Tile
13MB vs…
51.7MB Global File in TGFTP(25%)
13MB
233MB Global File in NOMADS (5%)

22. Quick tour over the bundle

23. Where to get it? Bundle and instructions available online:
international/gfs_sector_data/
Lets start a tour over the website...

24. Advantages Requirements
Advantages
-Save disk space and enhance
resolution simultaneously
-Faster download
-Faster processing times
-Be able to go back 12 days (data
in TGFTP available only for 1 day)
-Easy installation of Wingridds with
updated MACROS/scripts and
documentation
Requirements
-Windows. Works best in Windows 7 or newer.

25. Downloading & Installing
-Installer (executables .exe)
for 32 and 64 bits. You can install
by just executing the “.exe” file.
-Alternate options: zipped folders.
Unzip and extract the WINGRIDDS
folder into your C:/ folder
Note: Rename your C:/WINGRIDDS
Folder if you have it already installed
What will happen:
You will have a fresh version of Wingridds 3.2 installed. This includes all the current MACROS(scripts) used at the International Desks and their documentation.

26. Operating the Download Programs
Instructions available…
On the website
On readme files placed at “C:\WINGRIDDS\datosector_gfs\documentation” once the installer has been executed

27. Operating the Software
To download sector data just go to the folder
“C:\WINGRIDDS\datosector_gfs\en” or “C:\WINGRIDDS\datosector_gfs\es”
Scripts in English
Scripts in Spanish

28. Scripts in English Just double-click to run -Four for Mexico-Caribbean
C:\WINGRIDDS\datosector_gfs\en
-Four for Mexico-Caribbean
-Four for South America
-Available for each hour of initialization.
Just double-click to run
NOTE: Remember that data become available about 4-hours after initialization. This means that data for 00z will become available around 04z; for 06z around 10z and so on.

29. Scripts in Spanish Just double-click to run -Four for Mexico-Caribbean
C:\WINGRIDDS\datosector_gfs\es
-Four for Mexico-Caribbean
-Four for South America
Just double-click to run
Similar! Only differences:
Comments are in Spanish
The date is grabbed from your Windows System in a different manner (since in Spanish DD/MM/YYYY is used instead of MM/DD/YYYY). If needed, instructions to adjust the scripts to your Windows System and/or to fix the date explicitly are provided.

30. What will these programs do?
(1)Store the downloaded grib files in
C:\WINGRIDDS\GRIB\NWS
These can be used for whatever purpose you’d like, as long as you have a means to read them.

31. What will these programs do?
(2)Store the ready-to-use Wingridds file in the folder
“C:\WINGRIDDS\GRIDDATA\”
The extension will be “GFS255”
Can be opened with Wingridds

33. what can prevent GFS data downloading?
Bugs…
what can prevent GFS data downloading?
Date grabbed incorrectly from your PC/Laptop
Solution: Modify the variable
“date_string” in each program (details in website).
(2)Grib-to-Wingridds converter runs before all grib files have finished downloading (in some slower connections)
Solution: Run the converter manually and stop the programs
from running it by commenting the last two lines in
each program.
(3)Firewall issues that block the ports used to connect with the NOMADS server
Solution: Coordinate with your network administrator.

34. what can prevent GFS data downloading?
Bugs…
what can prevent GFS data downloading?
(4)Although sector limits can be modified, the Grib-to-Wingridds converter has some issues with some sectors.
Solution: Go back to a previous sector that worked. If it works
again stick to this one or try other coordinates.
This issue should be solved once the next
Wingridds update becomes available.

35. Questions?