NAM AIR QUALITY DIAGNOSTIC DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
1027 AM EDT TUE JUL 24 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). ***


...INTERIOR VALLEYS OF CALIFORNIA...
...LOWER COLORADO VALLEY...

THE NAM INITIALIZED SURFACE TEMPERATURES AS MUCH AS 15 TO 20
DEGREES TOO COOL NEAR THE MOUNTAINS...LIKELY DUE TO THE MODELS
TERRAIN RESOLUTION.


...FRONT RANGE OF COLORADO...

THERE WERE NO SIGNIFICANT INITIALIZATION ERRORS NOTED WITH THE NAM
OVER THIS REGION.


...NORTHEAST TEXAS...
...ARKLATEX...

THERE WERE NO SIGNIFICANT INITIALIZATION ERRORS NOTED WITH THE NAM
OVER THESE REGIONS.


...LOWER MISSOURI VALLEY...

THERE WERE NO SIGNIFICANT INITIALIZATION ERRORS NOTED WITH THE NAM
OVER THIS REGION.


...OHIO VALLEY...

THE NAM INITIALIZED SURFACE WINDS AS MUCH AS 10 KTS TOO
LIGHT...AND 50 DEGREES TOO NORTHERLY FROM THE EAST IN NORTHERN
ILLINOIS NEAR THE FRONTAL SYSTEM OVER THE REGION.


...MID ATLANTIC STATES...

THERE WERE NO SIGNIFICANT INITIALIZATION ERRORS NOTED WITH THE NAM
OVER THIS REGION.


CISCO