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

[Kickin Bears]

I'm trying to import LuckGrib data into the OpenCPN 5 Grib plugin, and running into issues when loaded.

For example, I've taken the NAM Grib file in LuckGrib, exported / saved, and loaded via OpenCPN. But the weather data is overlaying the Pacific Ocean as opposed to the continental US

Is there a way to align the imported Grib file with a chart coordinate?

See pic below.

[did-g]

You can get that kind of output for various reasons (aka OpenCPN bugs or missing grid definition).


Could you upload the grib file somewhere?

[Kickin Bears]

Will dropbox work? I can create a free account there to file share unless there's a way to post here

[CarCode]

Use zyGrib instead. It is free.

[did-g]

Originally Posted by Kickin Bears

Will dropbox work? I can create a free account there to file share unless there's a way to post here

If it's not too big (2MB) you can post it here, you might have to use a different extension though, adding .pdf should do, otherwise dropbox is fine.

[Kickin Bears]

@car code - will check out ZyGrib.

I already have Luck Grib and like it ... want to make an attempt at using OpenCPN with LG

@did-g - I'm juggling a few things atm. Will find a way to share the file. New to Mac here so I need to figure out how to change file extension, which should be easy (?). Will google it when I get back

Feel free to send guidance / source if handy. Appreciate your help

[Kickin Bears]

I figured out how to change the file extension on Mac ("control+click" >> get info >> find the file name w/ extension, and make the change); however, after renaming to .pdf the forum rejects as "invalid file". I tried .gif as an extension as well.

Here's an attempt at posting via Dropbox as public share:

https://www.dropbox.com/preview/Publ...?role=personal

Let me know if that works

[CarCode]

Originally Posted by Kickin Bears

@car code - will check out ZyGrib.
I already have Luck Grib and like it ... want to make an attempt at using OpenCPN with LG

LuckyGrib costs money and is not free as zyGrib. The grib plugin at OpenCPN is based on zyGrib and so you will be really lucky using it.

[Kickin Bears]

Re: being steered to zygrib, here is my feedback

*** I've already paid for Luck Grib, which is cheap (and the dollars support a nicely polished and supported final product), so I'd like to give that a go. Hoping did-g can take a look at the file and give some pointers.

*** I did download ZyGrib yesterday. The installation instructions are not well defined for a Mac (e.g. says to go to forums for installation specifics and yet at the forums, there's no sticky thread or identifiable / searchable / findable thread specific to Mac installation).

*** I did get the zygrib software to install and load, figured out how to download GRIB Data (which is extremely light compared to Luck Grib), and yet there are no basemaps loaded. I did download the high res basemaps but do not see a way to load them. Again the zygrib forums were not of any use, and on top of that when I clicked on "help" it literally said something along the lines of maybe we'll respond, maybe we won't, just click stuff and see what happens (a paraphrase but not far off from a quote either ... crazy!!)

*** I'd love to give zygrib a go, but in it's current form, lack of support, and lack of a manual supporting the use of a Mac, it's dead to me.

*** Luck Grib seems to be getting a bad rep for a mere a $20 (a one time fee no less). Given what I have seen in the ease of use, the volume of Grib files easily accessible, the amount of customization in parameters, and the fantastic display of the data / UI, I'm not sure I'm following why I'm being persistently steered away from Luck Grib. I've influenced some Luck Grib design issues in the tablet that were addressed after having exchanges with he developers, who were great to work with and still very accessible to me. Again, trying to understand why $20 is considered an obstacle when the upside is so much greater as compared to zygrib.

*** Free isn't always better, though I certainly applaud the effort the dev team is putting in. The Zygrib developer community is missing many software development and support service fundamentals though

Anyway, this isn't a zygrib thread and steering me away from it is a digression of the thread topic. Unless of course, the statement is "OpenCPN cannot / will not accept Grib 2 files from Luck Grib"

[did-g]

Originally Posted by Kickin Bears

I figured out how to change the file extension on Mac ("control+click" >> get info >> find the file name w/ extension, and make the change); however, after renaming to .pdf the forum rejects as "invalid file". I tried .gif as an extension as well.

Here's an attempt at posting via Dropbox as public share:

https://www.dropbox.com/preview/Publ...?role=personal

Let me know if that works

Hi, It doesn't work, in my understanding it's not the proper link, which should be something like:


https://www.dropbox.com/s/7ijujwrv283n13l//NAM.20191231.12.grb2?dl=0

[Kickin Bears]

@did-g — really appreciate your checking in. Will take a look again and repost

[Kickin Bears]

Ok ... lets try this one:

https://www.dropbox.com/s/a2qrzqt9xc...1.12.grb2?dl=0

[Dsanduril]

Kickin Bears,

I was able to download your last link and look at the file.

OpenCPN 4.84 on Windows 10 has the same result as your original post:



XyGrib 1.2.6 didn't open the file (unrecognized data, bad format, or...)

NOAA's WCT file viewer opened the file fine, allowed selection of data layers, etc.

[CarCode]

He should really look for a better source of grib data.
Paying money for such bad data is a crime.

[Dsanduril]

Actually, there doesn't seem to be any problem with the data. Every other full GRB2 viewer I have tried has decoded the file just fine. Currently using NASA's Panoply, it maps all of the data just fine. Reports the file metadata (below).

I suspect the problem probably starts with the Lambert Conformal projection of the data. OpenCPN (AFAIK) only supports Mercator and Transverse Mercator. Don't know if the Grib Plugin supports conversion on the fly when opening the GRB2 file.

@KB - Any chance Luck will allow you to download NAM in Mercator projection? Just curious if that would solve the issue, but absolutely zero knowledge on the internal coding of OpenCPN or the plugin in this regard.

File "NAM.20191231.12.grb2"
File type: GRIB2 Collection

netcdf file:/D:/Downloads/GRB2%20Test/NAM.20191231.12.grb2 {
dimensions:
x = 123;
y = 86;
time = 23;
time1 = 23;
height_above_ground = 1;
height_above_ground1 = 1;
isobaric = 2;
isobaric1 = 1;
variables:
int LambertConformal_Projection;
:grid_mapping_name = "lambert_conformal_conic";
:latitude_of_projection_origin = 25.0; // double
:longitude_of_central_meridian = 265.0; // double
:standard_parallel = 25.0; // double
:earth_radius = 6371229.0; // double

float x(x=123);
:standard_name = "projection_x_coordinate";
:units = "km";

float y(y=86);
:standard_name = "projection_y_coordinate";
:units = "km";

double reftime;
:units = "Hour since 2019-12-31T12:00:00Z";
:standard_name = "forecast_reference_time";
:long_name = "GRIB reference time";
:calendar = "proleptic_gregorian";

double time(time=23);
:units = "Hour since 2019-12-31T12:00:00Z";
:standard_name = "time";
:long_name = "GRIB forecast or observation time";
:calendar = "proleptic_gregorian";
:bounds = "time_bounds";

double time_bounds(time=23, 2);
:units = "Hour since 2019-12-31T12:00:00Z";
:long_name = "bounds for time";

double time1(time1=23);
:units = "Hour since 2019-12-31T12:00:00Z";
:standard_name = "time";
:long_name = "GRIB forecast or observation time";
:calendar = "proleptic_gregorian";

float height_above_ground(height_above_ground=1);
:units = "m";
:long_name = "Specified height level above ground";
ositive = "up";
:Grib_level_type = 103; // int
:datum = "ground";

float height_above_ground1(height_above_ground1=1);
:units = "m";
:long_name = "Specified height level above ground";
ositive = "up";
:Grib_level_type = 103; // int
:datum = "ground";

float isobaric(isobaric=2);
:units = "Pa";
:long_name = "Isobaric surface";
ositive = "down";
:Grib_level_type = 100; // int

float isobaric1(isobaric1=1);
:units = "Pa";
:long_name = "Isobaric surface";
ositive = "down";
:Grib_level_type = 100; // int

float Convective_available_potential_energy_surface(time 1=23, y=86, x=123);
:long_name = "Convective available potential energy @ Ground or water surface";
:units = "J/kg";
:abbreviation = "CAPE";
:missing_value = NaNf; // float
:grid_mapping = "LambertConformal_Projection";
:coordinates = "reftime time1 y x ";
:Grib_Variable_Id = "VAR_0-7-6_L1";
:Grib2_Parameter = 0, 7, 6; // int
:Grib2_Parameter_Discipline = "Meteorological products";
:Grib2_Parameter_Category = "Thermodynamic stability indices";
:Grib2_Parameter_Name = "Convective available potential energy";
:Grib2_Level_Type = 1; // int
:Grib2_Level_Desc = "Ground or water surface";
:Grib2_Generating_Process_Type = "Forecast";
:Grib2_Statistical_Process_Type = "UnknownStatType--1";

float Convective_inhibition_surface(time1=23, y=86, x=123);
:long_name = "Convective inhibition @ Ground or water surface";
:units = "J/kg";
:abbreviation = "CIN";
:missing_value = NaNf; // float
:grid_mapping = "LambertConformal_Projection";
:coordinates = "reftime time1 y x ";
:Grib_Variable_Id = "VAR_0-7-7_L1";
:Grib2_Parameter = 0, 7, 7; // int
:Grib2_Parameter_Discipline = "Meteorological products";
:Grib2_Parameter_Category = "Thermodynamic stability indices";
:Grib2_Parameter_Name = "Convective inhibition";
:Grib2_Level_Type = 1; // int
:Grib2_Level_Desc = "Ground or water surface";
:Grib2_Generating_Process_Type = "Forecast";
:Grib2_Statistical_Process_Type = "UnknownStatType--1";

float Dewpoint_temperature_height_above_ground(time1=23, height_above_ground1=1, y=86, x=123);
:long_name = "Dewpoint temperature @ Specified height level above ground";
:units = "K";
:abbreviation = "DPT";
:missing_value = NaNf; // float
:grid_mapping = "LambertConformal_Projection";
:coordinates = "reftime time1 height_above_ground1 y x ";
:Grib_Variable_Id = "VAR_0-0-6_L103";
:Grib2_Parameter = 0, 0, 6; // int
:Grib2_Parameter_Discipline = "Meteorological products";
:Grib2_Parameter_Category = "Temperature";
:Grib2_Parameter_Name = "Dewpoint temperature";
:Grib2_Level_Type = 103; // int
:Grib2_Level_Desc = "Specified height level above ground";
:Grib2_Generating_Process_Type = "Forecast";
:Grib2_Statistical_Process_Type = "UnknownStatType--1";

float Geopotential_height_isobaric(time1=23, isobaric=2, y=86, x=123);
:long_name = "Geopotential height @ Isobaric surface";
:units = "gpm";
:abbreviation = "HGT";
:missing_value = NaNf; // float
:grid_mapping = "LambertConformal_Projection";
:coordinates = "reftime time1 isobaric y x ";
:Grib_Variable_Id = "VAR_0-3-5_L100";
:Grib2_Parameter = 0, 3, 5; // int
:Grib2_Parameter_Discipline = "Meteorological products";
:Grib2_Parameter_Category = "Mass";
:Grib2_Parameter_Name = "Geopotential height";
:Grib2_Level_Type = 100; // int
:Grib2_Level_Desc = "Isobaric surface";
:Grib2_Generating_Process_Type = "Forecast";
:Grib2_Statistical_Process_Type = "UnknownStatType--1";

float Pressure_reduced_to_MSL_msl(time1=23, y=86, x=123);
:long_name = "Pressure reduced to MSL @ Mean sea level";
:units = "Pa";
:abbreviation = "PRMSL";
:missing_value = NaNf; // float
:grid_mapping = "LambertConformal_Projection";
:coordinates = "reftime time1 y x ";
:Grib_Variable_Id = "VAR_0-3-1_L101";
:Grib2_Parameter = 0, 3, 1; // int
:Grib2_Parameter_Discipline = "Meteorological products";
:Grib2_Parameter_Category = "Mass";
:Grib2_Parameter_Name = "Pressure reduced to MSL";
:Grib2_Level_Type = 101; // int
:Grib2_Level_Desc = "Mean sea level";
:Grib2_Generating_Process_Type = "Forecast";
:Grib2_Statistical_Process_Type = "UnknownStatType--1";

float Relative_humidity_height_above_ground(time1=23, height_above_ground1=1, y=86, x=123);
:long_name = "Relative humidity @ Specified height level above ground";
:units = "%";
:abbreviation = "RH";
:missing_value = NaNf; // float
:grid_mapping = "LambertConformal_Projection";
:coordinates = "reftime time1 height_above_ground1 y x ";
:Grib_Variable_Id = "VAR_0-1-1_L103";
:Grib2_Parameter = 0, 1, 1; // int
:Grib2_Parameter_Discipline = "Meteorological products";
:Grib2_Parameter_Category = "Moisture";
:Grib2_Parameter_Name = "Relative humidity";
:Grib2_Level_Type = 103; // int
:Grib2_Level_Desc = "Specified height level above ground";
:Grib2_Generating_Process_Type = "Forecast";
:Grib2_Statistical_Process_Type = "UnknownStatType--1";

float Temperature_isobaric(time1=23, isobaric1=1, y=86, x=123);
:long_name = "Temperature @ Isobaric surface";
:units = "K";
:abbreviation = "TMP";
:missing_value = NaNf; // float
:grid_mapping = "LambertConformal_Projection";
:coordinates = "reftime time1 isobaric1 y x ";
:Grib_Variable_Id = "VAR_0-0-0_L100";
:Grib2_Parameter = 0, 0, 0; // int
:Grib2_Parameter_Discipline = "Meteorological products";
:Grib2_Parameter_Category = "Temperature";
:Grib2_Parameter_Name = "Temperature";
:Grib2_Level_Type = 100; // int
:Grib2_Level_Desc = "Isobaric surface";
:Grib2_Generating_Process_Type = "Forecast";
:Grib2_Statistical_Process_Type = "UnknownStatType--1";

float Temperature_height_above_ground(time1=23, height_above_ground1=1, y=86, x=123);
:long_name = "Temperature @ Specified height level above ground";
:units = "K";
:abbreviation = "TMP";
:missing_value = NaNf; // float
:grid_mapping = "LambertConformal_Projection";
:coordinates = "reftime time1 height_above_ground1 y x ";
:Grib_Variable_Id = "VAR_0-0-0_L103";
:Grib2_Parameter = 0, 0, 0; // int
:Grib2_Parameter_Discipline = "Meteorological products";
:Grib2_Parameter_Category = "Temperature";
:Grib2_Parameter_Name = "Temperature";
:Grib2_Level_Type = 103; // int
:Grib2_Level_Desc = "Specified height level above ground";
:Grib2_Generating_Process_Type = "Forecast";
:Grib2_Statistical_Process_Type = "UnknownStatType--1";

float Total_cloud_cover_entire_atmosphere_single_layer(t ime1=23, y=86, x=123);
:long_name = "Total cloud cover @ Entire atmosphere layer";
:units = "%";
:abbreviation = "TCDC";
:missing_value = NaNf; // float
:grid_mapping = "LambertConformal_Projection";
:coordinates = "reftime time1 y x ";
:Grib_Variable_Id = "VAR_0-6-1_L200";
:Grib2_Parameter = 0, 6, 1; // int
:Grib2_Parameter_Discipline = "Meteorological products";
:Grib2_Parameter_Category = "Cloud";
:Grib2_Parameter_Name = "Total cloud cover";
:Grib2_Level_Type = 200; // int
:Grib2_Level_Desc = "Entire atmosphere layer";
:Grib2_Generating_Process_Type = "Forecast";
:Grib2_Statistical_Process_Type = "UnknownStatType--1";

float Total_precipitation_surface_Mixed_intervals_Accumu lation(time=23, y=86, x=123);
:long_name = "Total precipitation (Mixed_intervals Accumulation) @ Ground or water surface";
:units = "kg.m-2";
:abbreviation = "APCP";
:missing_value = NaNf; // float
:grid_mapping = "LambertConformal_Projection";
:coordinates = "reftime time y x ";
:Grib_Statistical_Interval_Type = "Accumulation";
:Grib_Variable_Id = "VAR_0-1-8_L1_Imixed_S1";
:Grib2_Parameter = 0, 1, 8; // int
:Grib2_Parameter_Discipline = "Meteorological products";
:Grib2_Parameter_Category = "Moisture";
:Grib2_Parameter_Name = "Total precipitation";
:Grib2_Level_Type = 1; // int
:Grib2_Level_Desc = "Ground or water surface";
:Grib2_Generating_Process_Type = "Forecast";
:Grib2_Statistical_Process_Type = "Accumulation";

float Composite_reflectivity_entire_atmosphere_single_la yer(time1=23, y=86, x=123);
:long_name = "Composite reflectivity @ Entire atmosphere layer";
:units = "dB";
:abbreviation = "REFC";
:missing_value = NaNf; // float
:grid_mapping = "LambertConformal_Projection";
:coordinates = "reftime time1 y x ";
:Grib_Variable_Id = "VAR_0-16-196_L200";
:Grib2_Parameter = 0, 16, 196; // int
:Grib2_Parameter_Discipline = "Meteorological products";
:Grib2_Parameter_Category = "Forecast Radar Imagery";
:Grib2_Parameter_Name = "Composite reflectivity";
:Grib2_Level_Type = 200; // int
:Grib2_Level_Desc = "Entire atmosphere layer";
:Grib2_Generating_Process_Type = "Forecast";
:Grib2_Statistical_Process_Type = "UnknownStatType--1";

float Visibility_surface(time1=23, y=86, x=123);
:long_name = "Visibility @ Ground or water surface";
:units = "m";
:abbreviation = "VIS";
:missing_value = NaNf; // float
:grid_mapping = "LambertConformal_Projection";
:coordinates = "reftime time1 y x ";
:Grib_Variable_Id = "VAR_0-19-0_L1";
:Grib2_Parameter = 0, 19, 0; // int
:Grib2_Parameter_Discipline = "Meteorological products";
:Grib2_Parameter_Category = "Physical atmospheric Properties";
:Grib2_Parameter_Name = "Visibility";
:Grib2_Level_Type = 1; // int
:Grib2_Level_Desc = "Ground or water surface";
:Grib2_Generating_Process_Type = "Forecast";
:Grib2_Statistical_Process_Type = "UnknownStatType--1";

float Wind_speed_gust_surface(time1=23, y=86, x=123);
:long_name = "Wind speed (gust) @ Ground or water surface";
:units = "m/s";
:abbreviation = "GUST";
:missing_value = NaNf; // float
:grid_mapping = "LambertConformal_Projection";
:coordinates = "reftime time1 y x ";
:Grib_Variable_Id = "VAR_0-2-22_L1";
:Grib2_Parameter = 0, 2, 22; // int
:Grib2_Parameter_Discipline = "Meteorological products";
:Grib2_Parameter_Category = "Momentum";
:Grib2_Parameter_Name = "Wind speed (gust)";
:Grib2_Level_Type = 1; // int
:Grib2_Level_Desc = "Ground or water surface";
:Grib2_Generating_Process_Type = "Forecast";
:Grib2_Statistical_Process_Type = "UnknownStatType--1";

float u-component_of_wind_isobaric(time1=23, isobaric=2, y=86, x=123);
:long_name = "u-component of wind @ Isobaric surface";
:units = "m/s";
:abbreviation = "UGRD";
:missing_value = NaNf; // float
:grid_mapping = "LambertConformal_Projection";
:coordinates = "reftime time1 isobaric y x ";
:Grib_Variable_Id = "VAR_0-2-2_L100";
:Grib2_Parameter = 0, 2, 2; // int
:Grib2_Parameter_Discipline = "Meteorological products";
:Grib2_Parameter_Category = "Momentum";
:Grib2_Parameter_Name = "u-component of wind";
:Grib2_Level_Type = 100; // int
:Grib2_Level_Desc = "Isobaric surface";
:Grib2_Generating_Process_Type = "Forecast";
:Grib2_Statistical_Process_Type = "UnknownStatType--1";

float u-component_of_wind_height_above_ground(time1=23, height_above_ground=1, y=86, x=123);
:long_name = "u-component of wind @ Specified height level above ground";
:units = "m/s";
:abbreviation = "UGRD";
:missing_value = NaNf; // float
:grid_mapping = "LambertConformal_Projection";
:coordinates = "reftime time1 height_above_ground y x ";
:Grib_Variable_Id = "VAR_0-2-2_L103";
:Grib2_Parameter = 0, 2, 2; // int
:Grib2_Parameter_Discipline = "Meteorological products";
:Grib2_Parameter_Category = "Momentum";
:Grib2_Parameter_Name = "u-component of wind";
:Grib2_Level_Type = 103; // int
:Grib2_Level_Desc = "Specified height level above ground";
:Grib2_Generating_Process_Type = "Forecast";
:Grib2_Statistical_Process_Type = "UnknownStatType--1";

float v-component_of_wind_isobaric(time1=23, isobaric=2, y=86, x=123);
:long_name = "v-component of wind @ Isobaric surface";
:units = "m/s";
:abbreviation = "VGRD";
:missing_value = NaNf; // float
:grid_mapping = "LambertConformal_Projection";
:coordinates = "reftime time1 isobaric y x ";
:Grib_Variable_Id = "VAR_0-2-3_L100";
:Grib2_Parameter = 0, 2, 3; // int
:Grib2_Parameter_Discipline = "Meteorological products";
:Grib2_Parameter_Category = "Momentum";
:Grib2_Parameter_Name = "v-component of wind";
:Grib2_Level_Type = 100; // int
:Grib2_Level_Desc = "Isobaric surface";
:Grib2_Generating_Process_Type = "Forecast";
:Grib2_Statistical_Process_Type = "UnknownStatType--1";

float v-component_of_wind_height_above_ground(time1=23, height_above_ground=1, y=86, x=123);
:long_name = "v-component of wind @ Specified height level above ground";
:units = "m/s";
:abbreviation = "VGRD";
:missing_value = NaNf; // float
:grid_mapping = "LambertConformal_Projection";
:coordinates = "reftime time1 height_above_ground y x ";
:Grib_Variable_Id = "VAR_0-2-3_L103";
:Grib2_Parameter = 0, 2, 3; // int
:Grib2_Parameter_Discipline = "Meteorological products";
:Grib2_Parameter_Category = "Momentum";
:Grib2_Parameter_Name = "v-component of wind";
:Grib2_Level_Type = 103; // int
:Grib2_Level_Desc = "Specified height level above ground";
:Grib2_Generating_Process_Type = "Forecast";
:Grib2_Statistical_Process_Type = "UnknownStatType--1";

// global attributes:
:Originating_or_generating_Center = "US National Weather Service, National Centres for Environmental Prediction (NCEP)";
:Originating_or_generating_Subcenter = "0";
:GRIB_table_version = "2,1";
:Type_of_generating_process = "Forecast";
:Analysis_or_forecast_generating_process_identifie r_defined_by_originating_centre = "MESO NAM Model (currently 12 km)";
:file_format = "GRIB-2";
:Conventions = "CF-1.6";
:history = "Read using CDM IOSP GribCollection v3";
:featureType = "GRID";
}