NAM AIR QUALITY DIAGNOSTIC DISCUSSION NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD 955 AM EDT WED AUG 08 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 TO 15 TOO COOL NEAR THE MOUNTAINS DUE TO ITS TERRAIN RESOLUTION. SNAKE RIVER VALLEY OF IDAHO... NORTHERN WASATCH FRONT... THERE WERE NO SIGNIFICANT INITIALIZATION ERRORS NOTED WITH THE NAM IN THESE REGIONS. 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. SOUTHERN ARKANSAS... THERE WERE NO SIGNIFICANT INITIALIZATION ERRORS NOTED WITH THE NAM IN THIS REGION. OHIO VALLEY... TENNESSEE VALLEY... THERE WERE NO SIGNIFICANT INITIALIZATION ERRORS NOTED WITH THE NAM IN THESE REGIONS. MID ATLANTIC STATES... THERE WERE NO SIGNIFICANT INITIALIZATION ERRORS NOTED WITH THE NAM IN THIS REGION. CISCO