NAM AIR QUALITY DIAGNOSTIC DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
1030 AM EDT WED JUN 01 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). ***

...SOUTHERN NEW ENGLAND...

THE 12Z NAM DID NOT INITIALIZE THE DEVELOPING BROKEN AXIS OF
CONVECTION SEEN STRETCHING FROM NEW HAMPSHIRE AND WESTERN
MAINE...SOUTHWARD DOWN INTO MASSACHUSETTS. SURFACE TEMPERATURES
WERE OBSERVED TO BE 5 TO 9 DEGREES F COOLER THAN INITIALIZED OVER
CENTRAL AND EASTERN MASSACHUSETTS...EASTERN CONNECTICUT AND RHODE
ISLAND.


...MID-ATLANTIC...

NO SIGNIFICANT INITIALIZATION ERRORS WERE NOTED.


...SOUTHEAST...

SURFACE TEMPERATURES WERE OBSERVED TO BE AS MUCH AS 5 TO 9 DEGREES
F COOLER THAN INITIALIZED OVER PORTIONS OF NORTHEAST ALABAMA AND
FAR WESTERN GEORGIA. 


...LOWER MISSISSIPPI VALLEY...

NO SIGNIFICANT INITIALIZATION ERRORS WERE NOTED.


ORRISON