[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[GEMPAK #VEM-684752]: couple GEMPAK7 odds and ends



> -- We download the NAM 4-km CONUS nest from NCEP (files like these):
> dcgrib2 -m 10000 -v 1 -d logs/dcgrib2_namnest.log -e GEMTBL=$GEMTBL -e 
> MDMETH=MDGDEC YYYYMMDDHHfFFF_nam4km.gem < 
> nam.t${START_HOUR}z.conusnest.hiresf${fcst_hours}.tm00.grib2
> It uses the grib2 table g2varsncep1.tbl to decode the variables, but
> there isn't an entry for "REFD" (simulated reflectivity) in that file.
> When I add an entry for REFD back in (like existed in older versions
> of GEMPAK, but not by default in v7) then it works fine.  I"m guessing
> there's probably a preferred workaround to this instead of what I did,
> but perhaps DCGRIB2 can be programmed to look elsewhere by default for
> that variable (or whatever the preferred method is).


Hi Russ,

I wanted to update you on the latest. I released GEMPAK 7.1.1 today and it 
contains the fix for this.  FWIW, REFD from changed to BREF sometime between 
GEMPAK 6.2 and 7.  I changed it back to REFD for the 7.1.1 release, and added 
more grib entries to handle the NGRID HRRR and the new 4km NAM.  The new grib2 
table can be found at

https://raw.githubusercontent.com/Unidata/gempak/master/gempak/tables/grid/g2varsncep1.tbl

The 7.1.1 release can be found at 

http://www.unidata.ucar.edu/downloads/gempak/index.jsp


> -- I'd like to use the new digital hybrid reflectivity (DHR) variable in
> the national composites to plot reflectivity (I've used n0r in the
> past).  But I'd also like to use a color table like the one the NWS
> uses.  I've used upc_rad24.tbl as the LUTFIL in the past, but when this
> is applied to DHR it changes up the values to which the colors
> correspond.  (e.g., in n0r, the red colors are in the ~50dBZ range and
> the scale tops out at ~75, but in DHR the red colors are in the 60dBZ
> range with the scale going up to 90+.  Examples images attached…I'm
> using GPMAP for the plotting, the only difference between my scripts is
> calling DHR instead of N0R.  I'm guessing there's a quick fix for this
> but I don't know what it is…any help would be appreciated.  

The default lutfil for level3 DHR is upc_dhr.tbl while the default for N0Q is 
upc_ref.tbl.  The latter was created from the operational AWIPS II base 
reflectivity color map, I think that's the one you're looking for.  I do like 
the feature resolution of upc_dhr.tbl, which shows more detail of outflow 
boundaries and near-surface waves.    That said, I changed back the default for 
all BREF products to upc_ref.tbl for this release.

Hope I answered your questions well.

Michael 


Ticket Details
===================
Ticket ID: VEM-684752
Department: Support GEMPAK
Priority: Urgent
Status: Open