NOUS41 KWBC 041403 AAA



Technical Implementation Notice 14-41 Amended

National Weather Service Headquarters Washington DC

900 AM EST Thu Dec 4 2014 


To:       Subscribers:

          -Family of Services

          -NOAA Weather Wire Service

          -Emergency Managers Weather Information Network


          Other NWS Partners, Users and Employees


From:     Timothy McClung

          Science Plans Branch Chief

          Office of Science and Technology


Subject:  Amended: Ozone Air Quality Prediction Update

          Effective January 27, 2015.


Amended to change implementation date from November 25, 2014, to

January 27, 2015


Effective on or about Tuesday, January 27, 2015, beginning with

the 1200 Coordinated Universal Time (UTC) run, the National

Centers for Environmental Prediction (NCEP) will upgrade the

Community Multi-scale Air Quality (CMAQ) modeling system that

provides ozone air quality predictions.


The updated CMAQ model includes an updated carbon bond gas phase

(CB05) mechanism and additional updates. This update is for the

contiguous 48 states (CONUS) domain.


Ozone predictions from the updated CMAQ model are available

through a parallel feed at the links below.






where YYYYMMDD is the year, month, day.  


The names of the CONUS grib files have changed to the following:







Additionally Alaska and Hawaii grib files are now available:











The CMAQ GRIB products from the parallel feed are also

disseminated via the NCEP website:


and the products will be displayed at:


The hourly ozone maps are available at:

The daily maximum ozone maps are available at

The current operational CMAQ model will continue providing

forecasts through


and displayed at


The scientific enhancements include the following:


-  Updated rate constants for Carbon Bond Mechanisms (CB05) 

-  Inclusion of monthly varying lateral boundary conditions

   for 36 gaseous and aerosol species below 7km altitude

-  Modified dry deposition velocity calculation

-  Constraint of planetary boundary layer height in the model

   to be at least 50m

-  Faster removal of organic nitrate from the atmosphere

-  Inclusion of particulate emissions from wildfires based on

   wildfire locations observed over the previous day

-  Suppression of soil emissions when terrain is covered by

   ice or snow

-  Inclusion of windblown dust emissions using threshold

   friction velocity and soil wetness fraction with

   climatological source composition and locations


There are no changes to existing products or their contents. 


Due to this upgrade, the CONUS products will be delivered 30 to

35 minutes later than in the past.


For questions or comments, contact:


Ivanka Stajner


Silver Spring, MD 20910

301 427 9103


NWS National Technical Implementation Notices are online at: