Opencpn and ECMWF grib issue

[Olly75]

Hi all I've recently started to use opencpn to view my grib files. I download them from predict wind via iridium.

To keep download sizes manageable I only down load GFS and ECMWF models.

The GFS loads into opencpn fine but if I try and load the ECMWF file I get an error message saying No valid GRIB file.

Has anyone come across this and if so is there an easy solution?

Many thanks.

[rgleason]

You could describe the ECMWF precisely, or upload to onedrive or dropbox and provide a link. Otherwise, we can't really help.

[B4A]

I have exactly the same issue.

On a Mac I installed the latest version of OpenCPN (5.2.4) and when I try to open grib files downloaded from PredictWind, the GFS grib loads fine, whereas the ECMWF does not load and I do not receive any error message.

You can download the ECMWF grib file I'm trying to use here:

https://gofile.io/d/AwuJUt

[CarCode]

I am afraid the ECMWF grib file type is not supported by OpenCPN. You can either try to install Panoply ( https://www.giss.nasa.gov/tools/panoply/download/ ) which also needs Java v9 to be installed on your Mac or you use zyGrib for downloading grib data.

[B4A]

Originally Posted by CarCode

I am afraid the ECMWF grib file type is not supported by OpenCPN. You can either try to install Panoply ( https://www.giss.nasa.gov/tools/panoply/download/ ) which also needs Java v9 to be installed on your Mac or you use zyGrib for downloading grib data.

Thanks,

can you please give me more details on why this specific PredictWind ECMWF grib file type is not supported by OpenCPN?

I would like to pass on this information to PredictWind to see if they can fix it.

Thanks!

[CarCode]

Originally Posted by B4A

Thanks,
can you please give me more details on why this specific PredictWind ECMWF grib file type is not supported by OpenCPN?
I would like to pass on this information to PredictWind to see if they can fix it.
Thanks!

I suggest to switch to zyGrib instead of PredictWind. zyGrib data is for free while offers of ECMWF are mostly not free and therefore they encrypted the data to take money from the users.

[B4A]

Originally Posted by CarCode

I suggest to switch to zyGrib instead of PredictWind. zyGrib data is for free while offers of ECMWF are mostly not free and therefore they encrypted the data to take money from the users.

I get ECMWF through PredictWind and IridiumGo! I like ECMWF, it's more reliable than GFS.

I'd like to understand why ECMWF is not compatible with OpenCPN. Is it because ECMWF is proprietary?

[rgleason]

Here is some information about the two models that you should be aware of.
https://blog.weather.us/model-mania-...hey-different/

The way ECMWF the organization is set up means that they can and do charge for their forecast data, though international law dictates that some of it (classified as WMO-Essential) is available for the public good. If you go to most free weather model sites, the only ECMWF data you’ll see is WMO-Essential, which only includes a small handful of parameters at a very low resolution.

OpenCPN is "open" because it is OpenSource Code and we also upport other opensource efforts such as Noaa GFS. The European Model is not opensource. I don't even know if the ECMWF data format is open. If it is open and available, it might be possible to adapt grib_pi to read it.



PS: Further down in the article there is more information about the two data models.

[B4A]

Originally Posted by rgleason

Here is some information about the two models that you should be aware of.
https://blog.weather.us/model-mania-...hey-different/

OpenCPN is "open" because it is OpenSource Code and we also upport other opensource efforts such as Noaa GFS. The European Model is not opensource. I don't even know if the ECMWF data format is open. If it is open and available, it might be possible to adapt grib_pi to read it.



PS: Further down in the article there is more information about the two data models.

Thanks for pointing me to that article, I found it very interesting. I agree with the author that the ECMWF consistently performs better than the GFS.

That's from my first end experience during the last 2 years of constantly checking in parallel the two model while sailing along the west coast of South Africa and Namibia, crossing to St Helena and Rio de Janeiro and sailing north across the coast of Brazil to the Caribbean.

For this reason I would like to be able to import the ECMWF grib into OpenCPN but if that's not possible, I can continue to display the ECMWF grib in PredictWind.

It's a pity though that OpenCPM can't read that file.

[CarCode]

Originally Posted by B4A

Thanks for pointing me to that article, I found it very interesting. I agree with the author that the ECMWF consistently performs better than the GFS.

You have to understand who is writing such informations and why. Of course the authors vote for their company. Don't believe the internet is a source of independet informations. It is full of fake...

[did-g]

Originally Posted by B4A

It's a pity though that OpenCPM can't read that file.

These files aren't distributed as GRIB for a couple of years, more exactly they are encrypted GRIB files.
In my understanding not doing that is against ECMWF license, there's a free ECMWF subset but it's very small.

They can't be read without extracting the distributor key.

[B4A]

Originally Posted by CarCode

You have to understand who is writing such informations and why. Of course the authors vote for their company. Don't believe the internet is a source of independet informations. It is full of fake...

You probably haven't read the part of my post when I said that in 2 years, 2 continents and 10,000 nautical miles sailed, ECMWF has been more reliable then GFS.

That being said, there is probably a reason why there are so many models other than GFS and ECMWF, and one model can't be right all of the times. Otherwise wouldn't have so many.

I quite don't understand your fixation against the ECMWF model.

[CarCode]

Originally Posted by B4A

I quite don't understand your fixation against the ECMWF model.

Simply because it is a commercial business model and here we are with open source only. You finaly get it now?

[CarCode]

By the way there is no godfather taking your dollars to make better weather for you...

[rgleason]

I expect that since this is open source code, if someone were to provide a good clean PR to support it, Bobcat would probably accept it.

However there are no excess programmers available for this big effort that I am aware of and I believe it would be pretty low on a list of priorities right now.

So if you want it so badly, program this improvement or get a friend to do it and make a PR.