The WRF ARW tests are conducted for the early summer period 1-31 May 2017 and for the winter period 1-28 January 2017. These two periods are selected because they encapsulated a broad range of weather regimes ranging from null to weak and strong events

  

A single domain with 415 x 325 horizontal grid points at the resolution of 15km is used for all tests. The domain is centered at (39N, -101W) with Lambert-Conformal map projection. There are 40 levels in the vertical.  
 
Two extra suites of 3km resolution runs are conducted for the period 1-31 May 2017 to test spectral bin microphysics and predicted particle property (P3) bulk microphysics.

 

domain 
 
Initial and boundary conditions are extracted from the NCEP GFS analysis product, which are in global 0.25 degree grids and at 6-hour intervals.  
 
Each single case is initialized daily at 0000UTC and run for 48-hour forecast. 31 and 28 cases are conducted  for the early summer and the winter 2017, respectively. 
 
Various combinations of physics options are tested with the focus on new features of WRFV4.2. Two baseline tests with the CONUS and TROPICAL suites are conducted using WRFV4.1.5 for comparison. 
 
Verification:
 
All WRF results are compared to 0.25 degree GFS surface and upper air analysis. Domain averaged BIAS and RMSE are calculated for conventional fields.
 
The results of the Conus suite are also verified against stations observations and soundings archived in GDAS historical dataset.
 
Precipitation from 15km and 3km runs are verified against StageIV observations.

 

 
 
Table 1 Configurations for tests conducted (unless specified, all tests are based on WRFV4.2)
Name
 
Radiation
 
Cumulus
 
MP_PHYS
 
SFCLAY
 
LAND
 
PBL
 
Conus 4.1.5
Conus 4.2
 
RRTMG
 
Modified Tiedtke
 
Thompson
 
Janjic
 
Noah
 
MYJ
 
Tropical  4.1.5
Tropical 4.2
 
RRTMG
 
New Tiedtke
 
WSM6
 
Old MM5
 
Noah
 
YSU
 
MSKF
 
RRTMG
 
MSKF
 
WSM5
 
Monin-Obukhov
 
Noah
 
YSU
 
BMJ
 
RRTMG
 
BMJ
 
WSM5
 
Monin-Obukhov
 
Noah
 
YSU
 
MYNN
 
RRTMG
 
MSKF
 
WSM5
 
MYNN
 
Noah
 
MYNN
 
IRR1-3
 
 
RRTMG
 
MSKF
 
WSM5
 
Monin-Obukhov
 
Noah
 
YSU
 
3DTKE
 
RRTMG
 
Modified Tiedtke
 
WSM5
 
Monin-Obukhov
 
Noah
 
OFF
 
FARMS
 
RRTMG
 
 
Modified Tiedtke
 
Thompson 
Janjic
 
Noah
 
YSU
 
FSBM (3km)
 
RRTMG
 
 
OFF
 
FSBM
 
Monin-Obukhov
 
Noah
 
YSU
 
P3 (3km)
 
RRTMG
 
OFF
 
P3
 
Monin-Obukhov
 
Noah
 
YSU