NOUS41 KWBC 041403 AAA
Technical Implementation Notice 14-41 Amended
National Weather Service Headquarters Washington DC
900 AM EST Thu Dec 4 2014
-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
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:
Silver Spring, MD 20910
301 427 9103
NWS National Technical Implementation Notices are online at: