NAM AIR QUALITY DIAGNOSTIC DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
1003 AM EDT THU AUG 09 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). ***


INTERIOR VALLEYS OF CALIFORNIA...
DESERT SOUTHWEST...

THE NAM INITIALIZED SURFACE TEMPERATURES AS MUCH AS 10 DEGREES TOO
LOW NEAR THE MOUNTAINS DUE TO ITS TERRAIN RESOLUTION.


SNAKE RIVER VALLEY OF IDAHO...
NORTHERN WASATCH FRONT...

THE NAM INITIALIZED SURFACE TEMPERATURES AS MUCH AS 10 DEGREES TOO
LOW NEAR THE MOUNTAINS DUE TO ITS TERRAIN RESOLUTION.


FRONT RANGE OF COLORADO...

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


CENTRAL OKLAHOMA...
EAST TEXAS...

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


OHIO VALLEY...
TENNESSEE VALLEY...

THE NAM INITIALIZED SURFACE WINDS AS MUCH AS 15 KTS TOO LOW
IMMEDIATELY NORTH OF THE FRONTAL BOUNDARY ASTRIDE THE OHIO RIVER.


MID ATLANTIC STATES...
SOUTHEAST PIEDMONT...

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


CISCO