This is a suite of scripts that proctor the execution of GEMPAK's nex2img to create NEXRAD composites. See IEM Website
Instead of using this, you really should just use MRMS and download data from their website. I do provide an archive of selected grib files here.
Limited integration testing is done on Github Actions: 
This repo bundles a RHEL8 built nex2img with the following diff applied. This
allows some logging to come to stderr, which is then used to produce metadata on
how many RADARs went into the composite.
diff --git a/gempak/source/programs/upc/programs/nex2img/nex2img.f b/gempak/source/programs/upc/programs/nex2img/nex2img.f
index 02abdc82..3737b9c8 100644
--- a/gempak/source/programs/upc/programs/nex2img/nex2img.f
+++ b/gempak/source/programs/upc/programs/nex2img/nex2img.f
@@ -218,6 +218,7 @@ C
CALL TB_RSTN(ilun,stid,stnnam, istnm, stat,
+ coun, slat, slon, selv, ispri, tbchars,
+ ierf )
+ write(*,*) 'Searching radar: ', stid
IF (ierf.eq.0) THEN
viewable = .true.
ifile = 1
@@ -256,6 +257,7 @@ C
radproj = 'RAD|D'
radarea = 'dset'
idrpfl = 0
+ write(*,*) 'Using image: ', imgfls
CALL GG_MAPS ( radproj, radarea, imgfls,
+ idrpfl, ier )
C