NAM AIR QUALITY DIAGNOSTIC DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
1008 AM EDT WED AUG 10 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). ***


...INTERIOR VALLEYS OF SOUTHERN CALIFORNIA...

THE NAM INITIALIZED AS MUCH AS 10-15 DEGREES TOO COOL NEAR THE
MOUNTAINS...AS A RESULT OF TERRAIN RESOLUTION.


...NORTHERN WASATCH FRONT...

THE NAM INITIALIZED 10 KNOTS TOO LIGHT WITH THE SURFACE WINDS NEAR
SALT LAKE CITY.


...NORTHERN AND CENTRAL FRONT RANGE OF COLORADO...

NO SIGNIFICANT MODEL INITIALIZATION ERRORS WERE NOTED OVER THIS
REGION.


...TENNESSEE VALLEY...

THE NAM APPEARS TO NOT HAVE RESOLVED THE SHOWER ACTIVITY
APPROACHING THE LOWER END OF THE VALLEY.


...EASTERN VIRGINIA AND NORTH CAROLINA...

NO SIGNIFICANT MODEL INITIALIZATION ERRORS WERE NOTED OVER THIS
REGION.


CISCO