NAM AIR QUALITY DIAGNOSTIC DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
1011 AM EDT WED JUN 29 2011
 
*** 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). ***


...THE INTERIOR VALLEYS OF CALIFORNIA...

THERE WERE NO SIGNIFICANT INITIALIZATION ERRORS WITH THE NAM
ACROSS THIS REGION.

...THE SOUTHWEST...

THE 29/12Z NAM INITIALIZED ABOUT 10-15F DEGREES TOO LOW WITH
SURFACE TEMPERATURES OVER PORTIONS OF THE LOWER COLORADO BASIN.
THERE IS A 5-10F DEGREE DIFFERENCE...TOO LOW/COOL OVER SOUTHEAST
ARIZONA...SOUTHERN UTAH AND SOUTHERN NEW MEXICO. 

...SOUTHERN PLAINS...

LOCAL WIND/TEMPERATURE FIELDS IN VICINITY OF CONVECTION AND
ASSOCIATED OUTFLOW OVER CENTRAL OKLAHOMA WERE NOT CAPTURED BY THE
29/12Z NAM.   

THE 29/12Z NAM IS 5-15F TOO LOW/COOL ACROSS PORTIONS OF WEST
CENTRAL AND NORTH CENTRAL TEXAS THIS MORNING. 

...THE MID ATLANTIC/SOUTHEAST...

THERE WERE NO SIGNIFICANT INITIALIZATION ERRORS WITH THE NAM
ACROSS THESE AREAS THIS MORNING.

VOJTESAK