NAM AIR QUALITY DIAGNOSTIC DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
1015 AM EDT FRI JUN 22 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/DESERT SOUTHWEST...
THE NAM IS 5-10F TOO COLD IN POCKETS ACROSS THE MOJAVE DESERT AND
CENTRAL VALLEY OF CALIFORNIA AND SIERRA NEVADA RANGE AND 5-15F TOO
WARM NEAR THE CALIFORNIA/MEXICO BORDER.  WINDS ARE MORE NORTHERLY
THAN THE NAM INDICATED ACROSS SOUTH-CENTRAL ARIZONA AND ARE 10-20
KNOTS TOO LIGHT ACROSS THE LAS VEGAS AREA AND NEAR THE SOUTHERN
SAN JOAQUIN VALLEY IN CALIFORNIA.


...COLORADO/UTAH/NEW MEXICO...
POCKETS OF CENTRAL COLORADO AND WEST-CENTRAL IDAHO ARE 5-10F
COLDER THAN THE NAM WITH PORTIONS OF WESTERN COLORADO 10-20F
WARMER THAN THE NAM.  WINDS ARE 10-15 KNOTS STRONGER THAN THE NAM
ACROSS PORTIONS OF EASTERN AND WESTERN COLORADO.


...EASTERN HALF OF THE COUNTRY...
WINDS ARE MORE SOUTHERLY THAN THE NAM INITIALIZED ACROSS WEST
VIRGINIA...SOUTHWEST PENNSYLVANIA...CENTRAL NORTH CAROLINA AND
SOUTH-CENTRAL VIRGINIA.  THERE HAS BEEN LESS RAIN THAN THE NAM
INDICATED ACROSS THE BLUE RIDGE MOUNTAINS AND WESTERN NORTH
CAROLINA.  MORE RAIN HAS FALLEN ACROSS WESTERN AND CENTRAL NEW
YORK AS WELL AS DOWNEAST MAINE THAN THE NAM INDICATED.  THE RAIN
THE NAM INDICATED ACROSS OKLAHOMA AND NORTHWEST PENNSYLVANIA NEVER
FELL.


ROTH