NAM AIR QUALITY DIAGNOSTIC DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
1030 AM EDT TUE JUN 07 2011
 
*** 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). ***

...OHIO/PENNSYLVANIA...

THE NAM IS SLOW TO DEVELOP THE MESOSCALE RAIN SYSTEM OVER EASTERN
OHIO AND WESTERN PENNSYLVANIA AND THUS IS UNDER-REPRESENTED
COMPARED TO RADAR. ALSO AS A RESULT...
OBSERVED TEMPERATURES ARE 3 TO 5 DEGREES COOLER THAN INITIALIZED.

...SOUTHEAST TEXAS...

THE COASTAL BOUNDARY BETWEEN GALVESTON AND CORPUS CHRISTI IS
POORLY RESOLVED IN THE NAM...WITH THE WIND DIRECTION ERRONEOUS BY
AS MUCH AS 60-90 DEGREES. 

...NEW MEXICO...

OBSERVED TEMPERATURES BETWEEN ALBUQUERQUE AND SANTE FE ARE MORE
CYCLONIC THAN INITIALIZED BY THE NAM...WHICH IS INDICATIVE OF A
WEAK AREA OF LOW PRESSURE...WHILE TEMPERATURES ARE AS MUCH AS 5 TO
10 DEGREE IN ERROR.

JAMES