NAM AIR QUALITY DIAGNOSTIC DISCUSSION NWS HYDROMETEOROLOGICAL PREDICTION CENTER COLLEGE PARK MD 1031 AM EDT THU AUG 30 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). *** ...MIDDLE ATLANTIC TO NYC METRO... NO NAM INITIALIZATION ERRORS WERE NOTED. ...UPPER MIDWEST TO TENNESSEE/OHIO VALLEYS... THE NAM DID NOT HAVE LIGHT/SCATTERED SHOWERS EXTENDING INTO CENTRAL MINNESOTA AS OBSERVED ON RADAR THIS MORNING. OTHERWISE...NO NAM INITIALIZATION ERRORS WERE NOTED. ...SOUTHERN PLAINS... NO NAM INITIALIZATION ERRORS WERE NOTED. ...INTERMOUNTAIN WEST...COLORADO FRONT RANGE AND EL PASO AREA... THE NAM ANALYZED TEMPERATURES ABOUT 5-10F TOO WARM IN THE COLORADO SPRINGS METRO REGION. THE NAM ANALYZED TEMPERATURES ABOUT 5-10F TOO COOL JUST EAST OF THE GREAT SALT LAKE IN UTAH. ...ARIZONA/CALIFORNIA INTO WESTERN NEVADA... THE NAM ANALYZED TEMPERATURES ABOUT 15F TOO WARM IN AND AROUND THE LAKE TAHOE REGION. 12Z WINDS FROM THE NAM WERE ABOUT 10 KT TOO WEAK COMPARED TO OBSERVATIONS ALONG THE SOUTHERN CALIFORNIA/NEVADA BORDER. OTTO