You may download as a single file or broken up into 100MB chunks.

Single zipped tar file:

646,029,587 Nov 29   conus12km_2001.tar.gz 

In pieces:

To reassemble:

  cat conus12km_2001_part* > conus12km_2001.tar.gz

104,857,600 Nov 29  conus12km_2001_part01 
104,857,600 Nov 29  conus12km_2001_part02 
104,857,600 Nov 29  conus12km_2001_part03 
104,857,600 Nov 29  conus12km_2001_part04 
104,857,600 Nov 29  conus12km_2001_part05 
104,857,600 Nov 29  conus12km_2001_part06 
 16,883,987 Nov 29  conus12km_2001_part07 

IMPORTANT UPDATE -- 20071208

Please note that the namelist.input file in the above tar distributions has settings that are different from the settings that were used for the benchmark results posted by vendors at http://www.mmm.ucar.edu/wrf/WG2/bench/results_20060515.html. Specifically, the wrong microphysics package is specified. You want WSM5 (mp_physics = 4,...) but the distributed namelist specifies the Eta microphysics (mp_physics=5,...). A link to the correct namelist to use for the 12km CONUS benchmark is here: namelist.input.