NAM AIR QUALITY DIAGNOSTIC DISCUSSION NWS HYDROMETEOROLOGICAL PREDICTION CENTER COLLEGE PARK MD 1036 AM EDT FRI AUG 17 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). *** ...WASHINGTON/OREGON/IDAHO/NORTHERN UTAH... NAM TEMPERATURES ACROSS NORTH IDAHO WERE 10F TOO WARM. SOUTHERN IDAHO TEMPERATURES WERE INITIALIZED 5F TOO COOL. WINDS ARE MORE NORTHERLY THAN INDICATED BY THE NAM ACROSS SOUTHERN OREGON AND MORE WESTERLY ACROSS CENTRAL WASHINGTON. ...CALIFORNIA/SOUTHERN NEVADA/ARIZONA... BETWEEN RIDGECREST AND MOJAVE CALIFORNIA, THE NAM WAS 10-15F TOO COOL. THE NAM WAS 5F TOO COOL NEAR NEEDLES CALIFORNIA. THE NAM DOES NOT HAVE THE CYCLONIC CIRCULATION INDICATED IN THE OBSERVATION FIELD NEAR SEDONA ARIZONA...WHICH LEADS TO WINDS WHICH ARE NOT WESTERLY ENOUGH IN SOUTHERN ARIZONA. WINDS BETWEEN PALM SPRINGS AND BARSTOW CALIFORNIA ARE 5-10 KNOTS TOO WEAK IN THE NAM. IT DOES NOT APPEAR THAN ANY OF THE NAM RAINFALL IN SOUTHERN CALIFORNIA HAS COME TO PASS THIS MORNING. ...COLORADO/FOUR CORNERS... THE NAM WAS 10-20F TOO COLD ACROSS SOUTHWEST AND WEST-CENTRAL COLORADO. ...TEXAS/OKLAHOMA/KANSAS CITY... NEAR SAN ANGELO AND HEARNE TEXAS, THE NAM WAS 5F TOO COOL. WINDS ACROSS CENTRAL AND SOUTHWEST OKLAHOMA ARE 5-10 KNOTS TOO LIGHT IN THE NAM. THE RAIN HAS PROGRESSED FARTHER SOUTH THAN THE NAM HAS ANTICIPATED ACROSS THE PINEY WOODS OF TEXAS. ...SOUTHEAST/MID-ATLANTIC STATES/COASTAL NEW ENGLAND... THE NAM WAS 5-10F TOO WARM IN NORTHERN NEW JERSEY, NORTH-CENTRAL MASSACHUSETTS, NEAR SARANAC LAKE NEW YORK, AND NEAR BERLIN NEW HAMPSHIRE. THE NAM WAS 5-10F TOO COOL ACROSS NORTHERN NEW YORK AND NORTHERN VERMONT. ROTH