Pacific Northwest Experimental WRF Weather Forecasts (Prior to 0Z April 15, 2008): Information

For a description of our current WRF and previous MM5 forecasts click here

General Information: The Department of Atmospheric Sciences at the University of Washington is now running the WRF mesoscale model version 2.2 once or twice a day in order to produce high resolution meteorological forecasts for the Pacific Northwest.

Model Configuration: The WRF forecasts currently attempt to mimic the outer 36-km, 12-km, and 4-km grids of our standard MM5 runs in horizontal and vertical resolution. The regions covered by each domain, showing topography and land use categories are shown in these plots:

Terrain		Land Use
WRF	WRF vs MM5	WRF	WRF vs MM5
36-km terrain	36-km Loop	36-km landuse	36-km Loop
12-km terrain	12-km Loop	12-km landuse	12-km Loop
4-km terrain	4-km Loop	4-km landuse	4-km Loop

The following tables list some of the major features of the model setup:

Options Starting with 2007033012 run and version 2.2 code:

Physics/Feature	Comments
4-km forecasts	0Z Runs Only Starting with 2007040300 run
CAM Longwave and Shortwave Radiation	ra_lw_physics = 3 and ra_sw_physics = 3 cam_abs_dim1 = 4, cam_abs_dim2 = 38, paerlev = 29, levsiz = 59
Thompson Microphysics	mp_physics = 8
Kain-Fritsch Cumulus	cu_physics = 1
YSU PBL	bl_pbl_physics = 1
Noah Land-Surface Model (initialized from NAM 221 grids)	sf_surface_physics = 2 and num_soil_layers = 4
Three-Dimensional Analysis Nudging to GFS Forecasts on 36-km Domain	grid_fdda = 1
One-way Nest, No feedback (like MM5)	feedback = 0 (prior to June 14, 2007 it was two-way nesting, unlike MM5)
Positive-definite Moisture Advection	pd_moist = .true. (prior to 0Z Aug 23, 2007 it was pd_moist = .false.)

Sample (most recent) WRF v2.2 namelist.input file

Phyics Options for runs from 2006040100 to 2007033000 with version 2.1.2 code:

Physics	Comments
RRTM Longwave and Dudhia Shortwave Radiation	ra_lw_physics = 1 and ra_sw_physics = 1
Thompson Microphysics	mp_physics = 8
Kain-Fritsch Cumulus	cu_physics = 1
YSU PBL	bl_pbl_physics = 1
5-layer Thermal Diffusion Soil Model	sf_surface_physics = 1 and num_soil_layers = 5
Snow cover effects included	ifsnow = 1

Phyics Options Prior to 2006040100 run with version 2.0.3.1 code:

Physics	Comments
RRTM Longwave and Dudhia Shortwave Radiation	ra_lw_physics = 1 and ra_sw_physics = 1
WSM 3-class Simple Ice Moist Physics	mp_physics = 3
Kain-Fritsch Cumulus	cu_physics = 1
YSU PBL	bl_pbl_physics = 1
5-layer Thermal Diffusion Soil Model	sf_surface_physics = 1 and num_soil_layers = 5

For the annotated namelist.input file we use, click here,