NAM AIR QUALITY DIAGNOSTIC DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER COLLEGE PARK MD
1038 AM EDT MON AUG 20 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). ***


...NORTHERN UTAH/SOUTHERN IDAHO/CENTRAL COLORADO...
THE NAM WAS 5F TOO WARM NEAR LOGAN UTAH AND ACROSS SOUTHERN IDAHO.
 THE NAM DID A POOR JOB DEPICTING THE SNAKE RIVER VALLEY TROUGH,
SHOWING WINDS WHICH WERE 5 KNOTS TOO WEAK AND NOT NORTHWESTERLY
ENOUGH IN BELLEVUE IDAHO.  WINDS WERE 5-10 KNOTS STRONGER THAN THE
NAM DEPICTION ACROSS EASTERN COLORADO.  NONE OF THE PRECIPITATION
THE NAM ADVERTISED NEAR THE CENTRAL MONTANA/IDAHO BORDER HAS COME
TO PASS. THE ACTIVITY ADVERTISED NEAR SPENCER IDAHO HAS OCCURRED,
THOUGH IT IS 70 MILES EAST-SOUTHEAST OF WHERE THE NAM WANTED IT.

...CALIFORNIA/SOUTHERN NEVADA/ARIZONA...
THE NAM WAS 5F-15F TOO WARM IN THE SOUTHEAST AND CENTRAL
CALIFORNIA, SOUTHERN ARIZONA, AND CENTRAL NEVADA.  WINDS BETWEEN
MOJAVE AND BARSTOW CALIFORNIA WERE 5 KNOTS TOO LIGHT ON THE NAM. 
THE NAM MISSED THE SHOWERS ACROSS SOUTHERN NEVADA AND NORTHERN
ARIZONA, WITH NONE OF ITS LIGHT PRECIPITATION ACROSS SOUTHERN
CALIFORNIA AND SOUTHERN ARIZONA VERIFYING.

...TEXAS/OKLAHOMA/KANSAS CITY...
THE NAM WAS 5F TOO COOL NEAR BROWNWOOD TEXAS.  THE NAM WAS TOO
EXTENSIVE WITH ITS PRECIPITATION SHIELD ACROSS SOUTHERN TEXAS,
WITH VERY LITTLE OF IT VERIFYING.

...SOUTHERN FLORIDA/SAVANNAH RIVER VALLEY/PENNSYLVANIA...
THE NAM DID A POOR JOB DEPICTING THE LAND BREEZE IN SOUTHERN
FLORIDA...SHOWING A WIND WHICH WAS TOO SOUTHERLY.  EXTREMELY
LITTLE OF THE NAM'S ADVERTISED PRECIPITATION NEAR THE
GEORGIA/SOUTH CAROLINA BORDER HAS OCCURRED.

...OHIO VALLEY/TENNESSEE VALLEY/PENNSYLVANIA...
THE NAM WAS MUCH TOO EXTENSIVE WITH ITS RAIN AREA OVER
PENNSYLVANIA, WITH LITTLE OF WHAT IT ADVERTISED IN SOUTHERN
SECTIONS OF THE STATE VERIFYING.

ROTH