alt Catalog http://mtarchive.geol.iastate.edu/thredds/catalog/mtarchive/1981/02/16/gempak/upperair/catalog.html

Dataset Size Last Modified
     Folder  upperair   --
         19810216_upa.gem 919.5 Kbytes 2015-12-28T15:06:11Z

ISU MTArchive at ISU MTArchive see Info
THREDDS Data Server [Version 4.6.14 - 2019-07-23T11:04:31-0600] Documentation