I’m not sure who this is from, but looks like it is probably someone at NCDC
Steve has never contacted NCDC about their “tampering”, but if he had he might have found at least a rudimentary understanding of the changes. Yes, there are many problems, but his use of the word “tampering” with its implication of conspiracy and fraud seems uncalled for. One can still criticize their methods and their conclusions without such language.
Herewith their rationale and their attempts to make the latest changes clear.
We switched to a new dataset in March 2014. It uses a much larger base of stations than the previous dataset, especially at the state level. It incorporates the topography of each state, rather than a simple average of the stations within the state (the whole record for high-terrain states will be cooler, because those high-terrain places are now represented).
We announced this change at the July 2011 American Meteorological Society’s Applied Climatology Conference:https://ams.confex.com/ams/19Applied/webprogram/Paper190591.html
We published its methodologies in the Journal of Applied Meteorology and Climatology:http://dx.doi.org/10.1175/JAMC-D-13-0248.1
We provided an explanation of the change on line months in advance at: http://www.ncdc.noaa.gov/monitoring-references/maps/us-climate-divisions.php
We provided a tool, months in advance of adoption, to allow users to compare and understand differences at the state, regional and national level: http://www.ncdc.noaa.gov/temp-and-precip/divisional-comparison/
We provided a webinar in early 2014: http://www1.ncdc.noaa.gov/pub/data/cirs/climdiv/nCLIMDIV-briefing-cirs.pdf
We notified several prominent applied climatology groups, including the American Association of State Climatologists
We provided a notification of the change on its monthly climate reports in the months before and after the transition. See: http://www.ncdc.noaa.gov/sotc/national/2014/2
We wrote a comprehensive “Frequently Asked Questions” about the transition with the February 2014 monthly climate report: http://www.ncdc.noaa.gov/sotc/national/2014/2/supplemental/page-5/
We included a notification of the change in the press highlights document accompanying the February 2014 report
and we provided technical updates in the weeks leading to the transition:http://www1.ncdc.noaa.gov/pub/data/cirs/div-dataset-transition-readme.txt (read from bottom up for chronology)