NAM AIR QUALITY DIAGNOSTIC DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
1027 AM EDT TUE JUN 05 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). ***


...SOUTHERN CALIFORNIA...

NAM SURFACE TEMPERATURES WERE INITIALIZED AS MUCH AS 20 DEGREES
TOO COLD WITHIN THE COACHELLA VALLEY AND 5-10 DEGREES TOO COLD IN
THE IMPERIAL AND LOWER COLORADO VALLEYS.

...LAKE TAHOE/RENO AREA...

NAM SURFACE TEMPERATURES WERE INITIALIZED APPROXIMATELY 10 DEGREES
TOO COLD EAST OF THE LAKE ACROSS THE RENO METROPOLITAN AREA. 
BOUNDARY LAYER WIND DIRECTIONS ACROSS THIS SAME AREA WERE
INITIALIZED TOO FAR TO THE SOUTH.