GFS Forecast automatic Access

Last update: Jan. 2018

 

    

    FOR PAY  - Contact us for a quotation

Automatic access to meteorological variables from GFS (NCEP) resource. Even if this resource is for free via the Web interface, we need to dimension our servers to welcome the large number of automatic requests. A fee is thus applied depending on the number of time series retrieved every day / month. Please  for a quotation and receive your SoDa credentials.

Automatic access with WGET - Automatic access with CURL

Download WGET.EXE

    

Automatic access with WGET

  1. Download wget.exe in a directory (Windows environment - by default available in Unix)
  2. In the same directory, create a text file and copy-paste in a single line the following instruction to test this permanent access to Carpentras, France.
    Beware the dates!!! GFS data are only available from one month ago up to day+3!
 

wget -O output_gfs_wget.csv --header="soda-user: guest" --header="soda-passwd: guest" ...
"http://www.soda-is.com/pub/gfs_forecast_request.php?geopoint=44.083,5.059&firstday=2018-01-01&lastday=2018-01-02&duration=h"

  1. Rename the text file with the .bat extension and double click on the .bat file to retrieve the output_gfs_wget.csv output file (Windows environment). Rename the text file with a .sh extension and run it using >my_script.sh in a Unix environment.

  The WGET command in details

Request:
wget -O output_gfs_wget.csv --header="soda-user: your_login" --header="soda-passwd: your_password" ...
"http://server/pub/gfs_forecast_request.php?geopoint=latitude,longitude&firstday=yyyy-mm-dd ...

&lastday=yyyy-mm-dd&duration=time_step"

Inputs:

  • your_login and your_password: this access is restricted to registered users, i.e. to users who purchased an automatic access to the data. Please contact us for a quotation or to receive your SoDa automatic access credentials 
  • Server: "www.soda-is.com" (main server) or "pro.soda-is.com" (mirror server)
  • latitude and longitude: in degrees, with at least 3 digits after comma, e.g. "geopoint=45.563,7.25"
  • yyyy-mm-dd: the first day and last day of your request, from one month ago up to day+3
  • time_step: "15" (minutes), "h" (hourly), "d" (daily), "m" (monthly). Automatic requests with a time step below 10 min are limited to one month, and automatic requests with a time step below one day limited to one year (identical to HelioClim-3 automatic request behavior).

Time reference is Universal Time.

Outputs:

Identical to the output columns received via the Web interface

  Recommendations - other links

Warning! It is strongly recommended to avoid the launch of parallel requests, using the "&" at the end of each wget request line. This would endanger our system.

More info about:

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Automatic access using CURL

You can also automatically retrieve GFS dataset using the CURL command as follows:

Request:
curl -F stations=@stations.txt -o output_gfs_curl.csv --header "soda-user: guest" --header "soda-passwd: guest" http://www.soda-is.com/pub/gfs_forecast_request.php

With the following stations.txt file format:
# Columns:
# id: station name
# latitude and longitude: in degrees, with at least 3 digits after comma
# elevation: ignored
# time reference: ignored
# duration: "15" (minutes), "h" (hourly), "d" (daily) or "m" (monthly)
# firstday and lastday: first and the last days of the request, expressed as yyyy-mm-dd
# slope of panel: ignored
# azimuth of panel: ignored
# ground_albedo: ignored
# horizon: ignored (optional)
# calibration: ignored (optional)
# format: ignored (optional)
#
#id         lat    lon   elevation time duration firstday lastday  slope azimuth albedo
Carpentras1 44.083 5.059 -999      UT   d        2018-01-13 2018-01-16 0.0   0.0     0.2
Carpentras2 44.083 5.059 -999      UT   h        2018-01-13 2018-01-16 0.0   0.0     0.2

Beware the dates!!! GFS data are only available from one month ago up to day+3!

NB: stations.txt is voluntarily identical to the one used to automatically retrieve satellite-derived solar radiation datasets HelioClim-3. Of course, a few parameters are not used to run GFS but are needed for the CURL request.

Please note that curl output does not contain headers.

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