Technical Implementation Notice 12-05: Corrected

National Weather Service Headquarters Washington DC

305 PM EST Fri Feb 3 2012


To:       Subscribers:

          - Family of Services

          - NOAA Weather Wire Service

          - Emergency Managers Weather Information Network

          - NOAAPORT

          Other NWS Partners and NWS employees


From:     Eli Jacks

          Chief, Fire and Public Weather Services Branch


Subject:  Corrected: Two Experimental Fire Weather Elements to be

          Added to the National Digital Forecast Database for

          the United States (CONUS and OCONUS), including Alaska,

          Hawaii, Guam and Puerto Rico, Effective February 15, 2012


Corrected to clearly state that this implementation is for all CONUS and OCONUS Weather Forecast Office (WFO) National Digital Forecast Database (NDFD) grids.


Effective Wednesday, February 15, 2012, at 1400 Coordinated

Universal Time (UTC), Daily Maximum and Minimum Relative

Humidity (RH) will be added to the National Digital Forecast

Database (NDFD) on an experimental basis for the United States

(CONUS and OCONUS), including Alaska, Hawaii, Guam and Puerto Rico. These elements are generated from computation of the existing hourly dew point and hourly temperature grids.


These two Fire Weather elements will be added to the NDFD for

the valid times shown:


- Maximum Relative Humidity (Days 1-7)

- Minimum Relative Humidity (Days 1-7)


More details regarding these new elements are available in the

Product Description Document (PDD) in the online catalog of

experimental NWS products and services.


With this implementation, these forecasts will be available from

NDFD in the standard methods:


- GRIdded Binary version 2 (GRIB2) files via Hypertext Transfer

  Protocol (HTTP) and File Transfer Protocol (FTP)


- eXtensible Markup Language (XML) via Simple Object Access

  Protocol (SOAP)

- Graphics via web browser




and XML services for Max/Min RH will become available within 45

days of the experimental release of GRIB2 files into NDFD.


Users who pull NDFD elements in GRIB2 format, either via the

internet or via the Family of Services (FOS) server access

service, may need to update their procedures and scripts in

order to access these new elements. The GRIB2 files are online




Partners and users who use the NDFD in XML via Web service or

the online graphical NDFD images can use the same methods they

currently use to acquire these new experimental elements.  The

NDFD Maximum/Minimum Relative Humidity elements will be labeled



More information about accessing and using NDFD elements is

online at:


If February 15, 2012, is declared a critical weather day, this

implementation may be postponed. In that case, users will be

notified of that decision via an updated Technical

Implementation Notice as far in advance as possible.


Comments and feedback on the experimental Maximum/Minimum

Relative Humidity NDFD elements will be accepted through August

31, 2012.  Links to online surveys for NDFD users are:


GRIB2 users:


Users OF XML SOAP service:


NDFD online graphics:


These new Maximum/Minimum Relative Humidity elements will remain

experimental until NWS assesses feedback and completes a

technical analysis.  At that time, the NWS will determine

whether to move these experimental elements to operational

status, discontinue them, or revise and retain them as

experimental elements.


For questions regarding these products, please contact:


  Heath Hockenberry

  National Fire Weather Program Manager

  NOAA/NWS Office of Climate, Water and Weather Services

  Boise, ID


For general questions regarding NDFD data, please email:


For technical questions regarding NDFD data, please contact:


  David Ruth

  Mesoscale Prediction Branch Chief

  NOAA/NWS Office of Science and Technology

  Silver Spring, Maryland


For questions regarding this notice, please contact:


  Robyn Heffernan

  Fire Weather Science and Dissemination Meteorologist

  NOAA/NWS Office of Climate, Water and Weather Services

  Boise, ID


Technical Implementation Notices specifically related to NDFD

are online at:


National Technical Implementation Notices are online at: