On December 24, 2013, U.S. EPA released an updated version of the AERMOD model, as well as the meteorological preprocessing program, AERMET.

http://www.epa.gov/ttn/scram/dispersion_prefrec.htm#aermod

The new versions are not anticipated to impact results significantly, rather the changes are more focused on new options associated with NO2 modeling and non-regulatory options for addressing low wind speed in meteorological data. The release of the updates will likely require any ongoing modeling work which has not previously been submitted to the agency, to be redone in the new AERMOD.

NCDAQ processes their own meteorological datasets which are then provided to applicants for their modeling projects. They have not yet indicated when/if they will be updating their data to the new AERMET version, so there will be much more information associated with this AERMOD update to come.