SUJET :

In the "What's new in XyGrib v1.2.6" section, it says "NOADD GFS Ensemble model can now be read"....but the GFS ensemble doesn't come up in the list of available models in XyGrib even though I have version 1.2.6
How do I access it?

Hello,
GFS is the NOADD GFS Ensemble which is the new GFS version provided by NOAA and replace the old version.

AhOkay écrit: In the "What's new in XyGrib v1.2.6" section, it says "NOADD GFS Ensemble model can now be read"....but the GFS ensemble doesn't come up in the list of available models in XyGrib even though I have version 1.2.6
How do I access it?

Hi,
XyGrib's interactive grib server (accessed via the 'Download' dialog window provides a set of the most commonly used gribs. However, the software can read many other grib files available, among them the GFS Ensemble files. All you need to do is to download the files you need from the source and then after your download (via browser or ftp etc.) just open the file in XyGrib using 'File->Open'.
The GFS Ensemble files are available on the NOMADS grib filter facility which allows downloading of subsets of the entire data.
David

DomH écrit: Hello,
GFS is the NOADD GFS Ensemble which is the new GFS version provided by NOAA and replace the old version.

The GFS and GFS ensemble are two separate things though. The GFS being the deterministic single-solution model and the GFS ensemble being its ensemble version with 20 perturbed forecast members and a control member.

davidgal écrit:

AhOkay écrit: In the "What's new in XyGrib v1.2.6" section, it says "NOADD GFS Ensemble model can now be read"....but the GFS ensemble doesn't come up in the list of available models in XyGrib even though I have version 1.2.6
How do I access it?

Hi,
XyGrib's interactive grib server (accessed via the 'Download' dialog window provides a set of the most commonly used gribs. However, the software can read many other grib files available, among them the GFS Ensemble files. All you need to do is to download the files you need from the source and then after your download (via browser or ftp etc.) just open the file in XyGrib using 'File->Open'.
The GFS Ensemble files are available on the NOMADS grib filter facility which allows downloading of subsets of the entire data.
David

The problem with using the NOMADS grib filter to download GFS ensemble data is that you have to manually download all of its 21 members individually, and also for every desired forecast time step because it only allows downloading of one file at a time.
So for example, if I wanted to use the ensemble data to display the maximum probability of precipitation for just one 24hr period, I'd have to download 21 x (total number of forecast time steps) = 21 x 4 = 84 individual files that need to be manually downloaded for the desired particular lat/lon domain, which would be extremely time consuming and tedious.

So I was hoping XyGrib could download all those required files in one shot and put them in a single combined grib2 file.

Unfortunately we have very little server resources and have to juggle with decisions on what to include and what is beyond our resources.
It is possible to script multiple downloads from NOMADS grib filter and then to concatenate the downloads.
XyGrib does not currently have a facility to switch between ensemble members in a composite file or to compare them side by side. This is something to consider in the future. Currently each member should be in a separate file. It is possible to open several instances of XyGrib each with a member to compare.

David