Mac - OpenCPN: Grib plugin - imported LuckGrib coordinates not loading properly

[Kickin Bears]

@CarCode - you're like a dog with a bone that wont stop! You’re doing me, the community, and yourself a disfavor in your responses. I don’t think the data is bad, and a single $20 payment is something that even the poorest of the poor can hustle up for a well developed, supported, and reliable viewer.

Plz start up another thread to continue your evangelical crusade to convert folks to zygrib.

@dsansuril - appreciate your validation and testing other viewers (as well as staying on topic). I’m just finishing up David Burch’s “modern marine weather” so I’m well versed in the data sets and viewers at this point. I don’t think anything is wrong with the data set either.

I’ll take a look when I’m home on my Mac for a mercator option. I’ll also ping the Luck Grib developer I was interacting with to see if they have any feedback

If I was able to merge OpenCPN ad hoc layering capabilities with the ease of requesting / viewing / exporting grib data from Luck Grib I’d be in heaven. Would love to overlay HRR and NAM data instead of being forced into GFS via OpenCPN as an example. Even better if I could layer synoptic data with forecasts overlaying a chart w/ position

@OpenCPN devs - Is the problem the Grib2 format?

[Dsanduril]

FWIW I don't find ZyGrib/XyGrib that useful. I may have to try Luck (never heard of it before) so thanks for that.

I reduced the data in two viewers to just MSL pressure. The OpenCPN plugin is correctly reading the data, and the contours look very similar, just in the wrong place and distorted, so I am suspecting more so now that it has something to do with the projection. If you look at the two pictures you'll see the large high over the central US appears to be the same structure shown in OpenCPN near Clarion.

[Dsanduril]

The Lambert Conformal projection in the file has a projection origin at 25N. OpenCPN has the center of the large high at ~18N, and the center is actually at ~42N, a difference of, curiously enough, ~25 degrees.

The difference in longitude appears to be about 8 degrees, which is probably just the distortion in the projections and locations.

[did-g]

Originally Posted by Kickin Bears

From where I sit, if I was able to merge OpenCPN ad hoc layering capabilities with the ease of requesting / viewing / exporting Grib data I’f be in heaven. Would love to overlay HRR and NAM data instead of being forced into GFS

@OpenCPN devs - Is the problem the Grib2 format?

Continental US HRR and NAM are using Lambert Conformal grid, openCPN is unable to open them. It's a work in progress so unlike Xygrib it doesn't return an error.
The good new is that Xygrib is able to read them now so OpenCPN should be able to do it soon...

[Kickin Bears]

Awesome did-g. Appreciate your taking a look and will keep my eyes peeled for the possibility of importing the Luck Grib data into OpenCPN later

I assume that GFS grib2 exports from Luck Grib should work ok?

Can test when I get home later.

@dsanduril and did-g ... you guys rock!

[Kickin Bears]

Quick follow on.

Tested a GFS file exported from Luck Grib, and it worked! Will definitely be using the export feature moving forward.

Look forward to seeing the Grib plugin evolve to include the other forecast models available!