NAM AIR QUALITY DIAGNOSTIC DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
1030 AM EDT MON JUL 16 2012


*** The following information pertains to initialization errors
noted on the 12Z NAM that may negatively impact the performance of
the 12Z CMAQ output as used for air quality forecasting.
Specifically, errors that apply to temperature, winds, relative
humidity and precipitation are included. This discussion only
applies to geographical regions of the CONUS where air quality is
currently forecast to be degraded (i.e. CODES:
YELLOW/ORANGE/RED/PURPLE/MAROON). ***


...COLORADO...

IN EASTERN COLORADO IN THE VICINITY OF COLORADO SPRINGS...THE NAM
IS INITIALIZED 10-15 DEGREES TOO COLD.

...IDAHO...

IN SOUTHWESTERN IDAHO...ALONG THE WESTERN SNAKE RIVER PLAIN...THE
NAM IS INITIALIZED 5-10 DEGREES TOO COLD.  BOUNDARY LAYER WINDS
ARE UNDERDONE BY AS MUCH AS 15 KNOTS ACROSS PARTS OF THIS REGION
AS WELL.

...SOUTHERN CALIFORNIA...

THE NAM IS SHOWING ITS TYPICAL COOL INITIALIZATION ACROSS SOME OF
THE INTERIOR VALLEYS...PARTICULARLY IN THE COACHELLA VALLEY WHERE
TEMPERATURES ARE AS MUCH AS 15 DEGREES TOO LOW.

...UPPER AND MID MISSISSIPPI VALLEY TO THE NORTHEAST/MID
ATLANTIC...
...SOUTHERN PLAINS TO THE SOUTHEAST...

NO SIGNIFICANT INITIALIZATION ERRORS WERE NOTED WITH THE 12Z NAM
IN THESE REGIONS.

PEREIRA