NOUS41 KWBC 241440



Technical Implementation Notice 11-52

National Weather Service Headquarters Washington DC

1040 AM EDT Wed Oct 24 2011


To:       Subscribers

          -Family of Services

          -NOAA Weather Wire Service


          -Emergency Managers Weather Information Network

          Other NWS Partners, Users and Employees


From:     Jay Lawrimore      

          Chief, Climate Analysis Branch

          National Climatic Data Center


SUBJECT:  Surface Temperature (Infrared) Calibration Revision for the Hourly02 and Daily01 Products

          Effective January 7, 2013


Effective Monday, January 7, 2013, at approximately 1500 Coordinated Universal Time (UTC), The National Climatic Data Center will add a surface temperature type field in the hourly02 (CRNH02) and daily01 (CRND01) products.  These revisions will affect the reported surface temperature (Infrared) for stations of the U.S. Climate Reference Network (USCRN) and the
U.S. Historical Climatology Network-Modernization (USHCN-M).


Presently, the surface temperatures values in these fields are being reported as uncorrected measurements; however, due to an ongoing equipment refresh to a new infrared surface temperature sensor model, USCRN is now also reporting corrected surface temperature measurements for some stations. These changes will impact previous users of the data because the corrected values will differ from uncorrected values.


To distinguish between uncorrected (raw) and corrected surface temperature measurements, a surface temperature type field will be added to the hourly02 and daily01 products. This new field will be one character in length and will immediately precede the existing surface temperature fields. For the hourly02, the new field will be inserted at column 125 with any following fields shifted forward by 2 characters. 


For the daily01, the new field will be inserted at column 88, with any following fields shifted forward by 2 characters.  The possible values of the new field will be "R" to denote raw surface temperature measurements, "C" to denote corrected surface temperature measurements, and "U" for unknown when measurements are missing.


The details of these changes will be online at:


For both products, the fields for average, maximum, and minimum surface temperature will remain 7 characters in length with one decimal place of precision, and report the temperature in degrees Celsius.


The documentation for the products will also be revised to clearly explain the purpose of the new surface temperature type field.


If you have questions or feedback, please contact:


  Scott Embler

  National Climatic Data Center

  151 Patton Ave

  Asheville , NC   28803



NWS Technical Implementation Notices are online at: