[gradsusr] GrADS help with NOMADS server

[Jeff Chabot]

I am running into two GrADS issues using sdfopen and NOMADS from NCEP.

Issue 1:

I am using GrADS to run some models for my website and just recently I
have been running into this error:

syntax error, unexpected WORD_STRING, expecting WORD_WORD
context: Error { code = 0; message =
"/gfs_0p25/gfs20210603/gfs_0p25_00z is not an available dataset"^;};

I am using the following sdfopen command:

sdfopen https://nomads.ncep.noaa.gov/dods/gfs_0p25/gfs20210603/gfs_0p25_00z

I have been using that format for years, but just the past few days I
have been receiving these errors.

Issue 2:

I believe that I am hitting the 120 connections limit despite adding
code to adjust for this limit:

I am now getting this error after defining one variable:

define precip = apcpsfc/25.4

gancgrid error: nc_get_vara_double failed; NetCDF: Malformed or
inaccessible DAP DATADDS
Data Request Error:  Error for variable 'apcpsfc'
  Error ocurred at column 1
DEFINE error:  Invalid expression.
gancgrid error: nc_get_vara_double failed; NetCDF: Malformed or
inaccessible DAP DATADDS
Data Request Error:  Error for variable 'apcpsfc'
  Error ocurred at column 1
DEFINE error:  Invalid expression.

I added a 60 second sleep command between variables to account for
your April 20th changes and things worked for a while, and now the
above error has returned.

GrADS code added:
say 'Sleep for 60 secs to Prevent Hitting 120 connection limit'
'!sleep 60'
say 'Continue Processing'

Any ideas or suggestions on these issues?  I had things working after
the April 20 NOMADS change, but since June, I have had these errors
and my code has stopped working.

P.S. Does anyone have sample code to check to see if sdfopen or define
commands will work and if not tell GrADS to quit so it doesn't waste
time creating blank maps?

Thanks again,


Jeff