[gradsusr] Curious why UGRDprs does not display properly inGrADS -data from new MSC CMC regional model

[Greg West]

Wesley and Lewis,

Thank you for addressing this.

I'm not sure if this will fix the other problem, which is that the CMC
grib2 files that wrap around the globe have the international date line
grid points twice (once at the western extent of the grid, and once at the
eastern extent of the grid). This means that, for example, the GDPS
high-res lat/lon grid (
http://dd.weatheroffice.ec.gc.ca/model_gem_global/high_resolution/grib2/lat_lon/)
has 360.6 degrees longitude. GrADS doesn't recognize this as a global
dataset since it's not 360 degrees, and so it doesn't plot properly. This
is occurs on the lat-lon projection data, which I'm not sure if Wesley's PS
update will fix.

To get around this, I've been subsetting the grib2 files to 360 degrees
after downloading them to get them to plot correctly in GrADS. The way I'm
doing this with wgrib2 takes ~15min for the hired GDPS lat-lon grid, which
is not ideal for producing forecast graphics for operational use. I'm glad
that CMC is testing the compatibility of their grib2 files with GrADS. I'll
re-download the latest wgrib2 and test it on the global lat-lon proj data
in the next day or so.

Greg
____________________________
Greg West, PhD
Postdoctoral Fellow
Weather Forecast Research Team
University of British Columbia
EOS-Main 224
GWest at eos.ubc.ca
--
Meteorologist
Hydrology & Technical Services
BC Hydro
Greg.West at bchydro.com
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