GMOS Case Study Land/Water Mask Change - MDL
GMOS Case Study Land/Water Mask Change
GMOS Development: December 2007 Gridded MOS Changes
On December 18, 2007, we will be making modifications to the GFS-based gridded MOS guidance for the CONUS. Based on feedback we have received from users of the gridded MOS, we will:
1) modify the mask that designates whether a gridpoint is land or water (land/water mask)
used in the analysis process
2) modify the QPF analysis scheme, and
3) remove stations from the analysis
More details are provided below.
Change 1: Modifications to Land/Water Mask
Images for Comparison (PDF images)
Change 2: Change to Precipitation Amount analysis scheme
The analysis was modified slightly because it was felt our expected value approach was too conservative. This new method results in higher precipitation amounts.
Current Precipitation Amount
Precipitation Amount with new scheme
Change 3: Removal of stations from analysis
The following list of stations will be removed from the analysis for the given elements based on user feedback indicating these stations were causing errors in the analysis.
|Max/Min Temperature||KHZY -- Ashtabula, OH|
|171381/CHAM1 -- Chamberlain Bridge, ME -- cooperative observer site|
|Dew point Temperature||KTZR -- Columbus/Bolton Field, OH|
|KIDI -- Stewart Field, PA|
|All elements||QOSA3 -- Piney Hill, AZ - mesonet site|
|NS006 -- O W Saddle, AZ - mesonet site|