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