Pacific Northwest Mesoscale Model Weather Forecasts: Information

For a description of the MM5-NAM forecasts click here

For a description of our older, experimental WRF forecasts click here

For a description of our older, real-time MM5 forecasts click here

General Information: The Department of Atmospheric Sciences at the University of Washington is now running the Advanced Research WRF (WRF-ARW) core of the Weather Research and Forecasting Model (WRF) version 3.7.1 (WRF-ARW v3.7.1). Forecasts are run twice a day in order to produce high resolution meteorological guidance for the Pacific Northwest. This effort, supported by a consortium of local, state, and federal agencies, has several goals:


Change Log: For the latest information on our setup, please consult the Change Log for Pacific Northwest WRF/MM5 Numerical Forecasts

Model Configuration: The WRF numerical forecasts currently feature an outer grid of 36 km horizontal resolution that covers much of western North America and the northeastern Pacific; a nested grid of 12 km resolution that covers Washington, Oregon, Idaho, Utah, much of Montana and Nevada, southern British Columbia, and northern California; and an inner 4 km resolution grid encompassing all of Washington, Oregon, and Idaho plus the western third of Montana and the extreme northern sections of California, Nevada, and Utah, and the western third of Wyoming. A high-resolution 4/3-km domain is also run which covers Washington, Oregon, the western portion of Idaho, and the extreme southern 40-50 km of British Columbia. The regions covered by each domain, showing topography and land use categories are shown in these plots:
New version
Compatible with WRF
Old version
from TERRAIN
TerrainLand UseTerrainLand Use
36-km terrain 36-km land use 36-km terrain 36-km land use
12 km terrain 12 km land use 12 km terrain 12 km land use
4 km terrain 4 km land use 4 km terrain 4 km land use
1.33 km terrain 1.33 km land use 1.33 km terrain 1.33 km land use
A land use category color key is included in the links above, you may view it alone here. And, the USGS landuse color key is here.

A detailed description of the domain boundaries can be found in the actual geogrid.exe namelist.wps file or in the MM5 terrain.deck. Detailed land use information for each domain was derived from the 1-km MODIS digital database.

The model utilizes 38 vertical full-eta levels see below, and is run in non-hydrostatic mode in order to limit pressure gradient force errors over the complex terrain. An upper-radiative boundary condition is used to allow gravity waves to radiate through the model top without being reflected. The following table describes the phyics options we are currently using:

Phyics and Other Options:
PhysicsComments
Radiation RRTMG shortwave and longwave radiation schemes.
Thompson MicrophysicsIncludes graupel.
Grell-Freitas ensemble scheme for Cumulus Convection Begain using Grell-Freitas with the 2015110312 run. Prior to that, the Simplified Arakawa-Schubert scheme was used from 2012122100-2015110300.
The old Kain-Fritsch scheme was used through 2012122012, but non-physical lines of accumulated precipitation (see here) forced us to drop it.
YSU PBLYonsei University scheme (new MRF). Non-local-K scheme with explicit entrainment layer and parabolic K profile in unstable mixed layer. NOTE: the module_bl_ysu.F from version 3.0 of the WRF was backported into the version 2.2.1 WRF that was run up to and including the 2009010900 case.
Noah-MP Land Surface Model Beginning with the 2015012900 case, we have switched to the Noah-MP which uses multiple options for key land-atmosphere interactions. As noted in the documentaion: Noah-MP contains a separate vegetation canopy defined by a canopy top and bottom with leaf physical and radiometric properties used in a two-stream canopy radiation transfer scheme that includes shading effects. Noah-MP contains a multi-layer snow pack with liquid water storage and melt/refreeze capability and a snow-interception model describing loading/unloading, melt/refreeze, and sublimation of the canopy-intercepted snow. Multiple options are available for surface water infiltration and runoff, and groundwater transfer and storage including water table depth to an unconfined aquifer. Horizontal and vertical vegetation density can be prescribed or predicted using prognostic photosynthesis and dynamic vegetation models that allocate carbon to vegetation (leaf, stem, wood and root) and soil carbon pools (fast and slow).
aer_opt = 2 (summer months only) Running from the 2018081600 run to the 2018100312 forecast, we used the aer_opt = 2 settings, adding the predicted 2-d aerosol optical depth (AOD) at 550 nm (AOD5502D in WRF) and the predicted 2-d aerosol Angstrom exponent (ANGEXP2D in WRF) from NASA's GEOS-5 system.

WRF's aerosol single-scattering albedo (AERSSA2D) and aerosol asymmetry factor (AERASY2D) are set to the recommended fixed values of 0.85 and 0.9, respectively.
See the latest 36/12/4 km namelist.input and 4/3 km namelist.input for a complete list of the aerosol settings.

Here are the exact namelist.input files that are used to run the model: 36/12/4 km namelist.input and 4/3 km namelist.input (these two links are updated with each model run.). For more information on any of these options, see the WRF model chapter of the WRF User's Guide.


Initializations: Currently two model runs are performed. One utilizes initial and lateral boundary conditions for an older MM5 run that are generated by interpolation of the National Centers for Environmental Prediction (NCEP) "NAM" (formerly the ETA) model analysis and forecast fields. This MM5-NAM run only includes the 36 and 12 km domains and is described here.
The second initialization uses NCEP's GFS model (formerly known as AVN or MRF) at 0.5-degree lat/lon resolution for nearly all fields. The exceptions are: 1) SST is from the 1/4 degree OTIS grids, 2) surface temperature and 3-D moisture fields are from the Rapid Update Cycle 130 grids where available. Alternatively, when the RAP 130 grids are unavailable, surface temperature is from the NAM/ETA 221 grids (40-km grid spacing), and 3) subsurface soil temperature and moisture are also from NAM/ETA 221 grids.
Forecast: Forecasts are computed as follows:
  1. MM5-NAM: 4-processor Intex Xeon Linux box.
  2. WRF-GFS: Eight 20-processor Intel Xeon cluster running Debian Linux .
Currently, the model is run for 84 hour forecast period for the 36, 12, and 4-km domains. For the 4/3-km domain, it is run for 60 hours. An extended run to 180 hours is also run for the 36 and 12-km domains. The MM5-NAM finishes in roughly 22 minutes of wallclock time, while the WRF-GFS finishes in roughly 1.75 hours of wallclock time for the 36/12/4 and 4 hours for the 4/3-km domain.
Future Improvements: The modeling system is constantly being improved.

Vertical Levels

 October 11, 2012 and after Eta levels:
        1.000,  0.995,  0.990,  0.9841, 0.9772, 
	0.9702, 0.9620, 0.9525, 0.9414, 0.9284, 
	0.9134, 0.8960, 0.8759, 0.8527, 0.8260, 
	0.7955, 0.7608, 0.7218, 0.6785, 0.6309, 
	0.5785, 0.5213, 0.4594, 0.3953, 0.3360, 
	0.2832, 0.2363, 0.1951, 0.1595, 0.1291, 
	0.1031, 0.0806, 0.0612, 0.0449, 0.0312, 
	0.0194, 0.0091, 0.000

 pre-October 11, 2012 Eta levels:
         1.00, 0.995*, 0.99, 0.985*, 0.98, 0.97, 0.96, 0.95*, 
         0.94, 0.93*, 0.92, 0.91*, 0.90,
         0.88, 0.86, 0.83, 0.80, 0.77, 0.74, 0.71,
         0.68, 0.64, 0.60, 0.56, 0.52, 0.48, 0.44, 0.40, 
         0.36, 0.32, 0.28, 0.24, 0.20, 0.16, 0.12, 0.08, 0.04, 0.
	 * = added 7/9/2001
October 11, 2012 Values
K Level Half-eta Average Half-eta Height meters Max Half-eta hgt Min Half-eta hgt Full eta Average Full-eta Height meters Max Full-eta hgt Min Full-eta hgt
1 0.9975 20.01 21.76 17.37 1.0000 0.00 0.00 0.00
2 0.9925 60.14 65.24 52.22 0.9950 40.07 43.59 34.79
3 0.9870 104.06 112.70 90.34 0.9900 80.28 87.02 69.69
4 0.9806 155.84 168.52 135.32 0.9841 127.91 138.48 111.05
5 0.9737 212.34 229.89 184.41 0.9772 183.87 198.90 159.67
6 0.9661 274.45 297.37 238.37 0.9702 240.93 261.01 209.23
7 0.9572 347.20 376.07 301.61 0.9620 308.12 333.91 267.62
8 0.9469 432.49 467.83 375.79 0.9525 386.49 418.47 335.76
9 0.9349 533.12 575.76 463.39 0.9414 478.77 517.51 416.04
10 0.9209 651.27 702.39 566.30 0.9284 587.87 634.47 511.03
11 0.9047 789.71 850.61 686.95 0.9134 715.21 770.93 621.98
12 0.8859 952.38 1024.45 828.73 0.8960 864.97 931.14 752.50
13 0.8643 1143.57 1228.60 995.36 0.8759 1040.82 1118.93 905.75
14 0.8393 1368.62 1469.72 1191.42 0.8527 1247.76 1340.45 1086.06
15 0.8108 1633.19 1752.33 1421.68 0.8260 1491.46 1601.26 1298.29
16 0.7781 1944.06 2083.12 1691.63 0.7955 1777.67 1906.51 1547.14
17 0.7413 2308.25 2469.21 2006.75 0.7608 2114.23 2263.99 1838.95
18 0.7002 2732.27 2917.91 2371.74 0.7218 2507.42 2680.22 2178.39
19 0.6547 3223.99 3439.84 2791.93 0.6785 2964.11 3164.19 2570.22
20 0.6047 3796.47 4047.27 3276.77 0.6309 3493.24 3726.03 3020.41
21 0.5499 4466.74 4757.06 3839.36 0.5785 4112.51 4382.91 3542.21
22 0.4904 5253.84 5587.76 4495.31 0.5213 4838.58 5150.88 4148.78
23 0.4273 6166.18 6550.76 5257.62 0.4594 5693.55 6053.46 4858.65
24 0.3656 7157.64 7593.81 6103.25 0.3953 6670.77 7083.43 5679.05
25 0.3096 8164.29 8667.74 6990.52 0.3360 7678.41 8150.30 6552.94
26 0.2598 9170.20 9743.08 7903.57 0.2832 8683.90 9226.51 7455.25
27 0.2157 10175.10 10808.09 8833.16 0.2363 9690.29 10297.93 8380.44
28 0.1773 11173.24 11850.76 9763.55 0.1951 10693.47 11355.55 9315.00
29 0.1443 12157.46 12856.74 10679.04 0.1595 11685.79 12381.04 10240.68
30 0.1161 13126.38 13823.99 11573.48 0.1291 12660.88 13364.77 11144.66
31 0.0918 14088.39 14764.01 12451.86 0.1031 13622.78 14313.21 12028.33
32 0.0709 15050.06 15688.55 13316.87 0.0806 14584.89 15243.69 12900.79
33 0.0531 16000.05 16593.02 14125.34 0.0612 15546.10 16161.50 13757.44
34 0.0380 16926.77 17473.61 14834.83 0.0449 16483.38 17050.93 14497.17
35 0.0253 17842.37 18348.20 15518.01 0.0312 17398.45 17921.57 15188.43
36 0.0143 18766.27 19240.66 16188.24 0.0194 18314.66 18800.60 15862.75
37 0.0046 19713.78 20199.06 16853.24 0.0091 19247.18 19723.37 16528.52
38 0.0000 0.00 0.00 0.00 0.0000 20211.72 20707.03 17192.67
Pre-October 11, 2012 Values
K LevelHalf-etaHalf-eta Height
meters
Full-etaFull-eta Height
meters
10.997520.0521.00000.000
20.992560.2660.995040.157
30.9875100.5960.990080.429
40.9825141.0440.9850120.818
50.9750201.9120.9800161.324
60.9650283.5700.9700242.720
70.9550365.7610.9600324.645
80.9450448.5110.9500407.104
90.9350531.8530.9400490.149
100.9250615.7940.9300573.791
110.9150700.3350.9200658.035
120.9050785.4750.9100742.874
130.8900914.2190.9000828.318
140.87001088.3380.88001001.116
150.84501309.6660.86001176.588
160.81501581.6050.83001445.151
170.78501861.0360.80001720.590
180.75502149.0000.77002004.163
190.72502446.5510.74002296.693
200.69502754.4500.71002599.469
210.66003126.7700.68002912.706
220.62003570.6910.64003347.130
230.58004034.7630.60003801.129
240.54004520.4820.56004275.920
250.50005030.4090.52004773.298
260.46005568.4400.48005296.660
270.42006138.6200.44005850.452
280.38006744.5930.40006438.319
290.34007390.1480.36007063.924
300.30008080.8110.32007731.229
310.26008825.1450.28008447.510
320.22009635.1260.24009222.832
330.180010526.7500.200010071.440
340.140011522.1600.160011011.530
350.100012655.8200.120012070.160
360.060013987.3600.080013291.180
370.020015621.6600.040014754.950
380.00000.0000.000016601.950


Past Domain Configurations: This table provides all the necessary information about previous domain configurations.
Domain NameCode VersionFirst ForecastLast Forecast 36 km Domain 12 km Domain 4 km Domain 4/3 km Domain Terrain Setup File Full TER.PLT NCGM File
TerrainLand useWidth x Height, Lat, Lon, Elev and Domain Extents TerrainLand useWidth x Height, Lat, Lon, Elev and Domain Extents TerrainLand useWidth x Height, Lat, Lon, Elev and Domain Extents TerrainLand useWidth x Height, Lat, Lon, Elev and Domain Extents
nov163.7.1 with MODIS landuse, Grell cumulus, Noah-MP LSM2016110100 present terrain land use 151x127 terrain land use 184x142 terrain land use 406x283 terrain land use 712x664 terrain.deck TER.PLT
nov153.7.1 with MODIS landuse, Grell cumulus, Noah-MP LSM20151103122016103112 terrain land use 151x127 terrain land use 184x142 terrain land use 406x283 terrain land use 712x364 terrain.deck TER.PLT
jan153.6.1 with MODIS landuse20150129002015110300 terrain land use 151x127 terrain land use 184x142 terrain land use 406x283 terrain land use 712x364 terrain.deck TER.PLT
sep133.5 with MODIS landuse
3.5 with USGS landuse
2013110900
2013091612
2015012812
2013110812
terrain land use 151x127 terrain land use 184x142 terrain land use 406x283 terrain land use 712x364 terrain.deck TER.PLT
oct123.4.1 with SAS cumulus
3.4.1 with old Kain-Fritsch
2012122100
2012101100
2013091600
2012122012
terrain land use 151x127 terrain land use 184x142 terrain land use 406x283 terrain land use 712x364 terrain.deck TER.PLT
oct113.1.120111017122012101012 terrain land use 151x127 terrain land use 184x142 terrain land use 406x283 terrain land use 712x364 terrain.deck TER.PLT
dec103.1.120110113122011101712 terrain land use 151x127 terrain land use 169x142 terrain land use 346x265 terrain land use 532x364 terrain.deck TER.PLT
dec093.1.120091231002011011300 terrain land use 151x127 terrain land use 169x142 terrain land use 346x265 terrain land use 301x244 terrain.deck TER.PLT
apr083.0.1.1 from 2009010912
2.2.1 until 2009010900
20080415002009123012 terrain land use 151x127 terrain land use 169x142 terrain land use 346x265 NA NA NA terrain.deck TER.PLT
may063-7-320060515122008041412 terrain land use 151x127 terrain land use 163x124 terrain land use 307x220 NA NA NA terrain.deck TER.PLT
dec033-6-320040209122006051500 terrain land use 151x127 terrain land use 163x124 terrain land use 307x220 NA NA NA terrain.deck TER.PLT
aug023-5-420020909122004020900 terrain land use 151x127 terrain land use 151x112 terrain land use 205x220 NA NA NA terrain.deck TER.PLT
jun013-420010709122002090900 terrain land use 151x127 terrain land use 151x112 terrain land use 187x220 NA NA NA terrain.deck TER.PLT
jul002-1220000731122001070900 terrain land use 151x127 terrain land use 112x106 terrain land use 187x220 NA NA NA terrain.deck TER.PLT
dec992-1219991213002000073100 terrain land use 137x101 terrain land use 103x100 terrain land use 172x124 NA NA NA terrain.deck TER.PLT
may992-12 and 2-719990518121999121212 terrain land use 137x101 terrain land use 88x88 terrain land use 94x94 NA NA NA terrain.deck TER.PLT
mar982-719980318121999051800 terrain land use 137x101 terrain land use 82x82 terrain land use 94x94 NA NA NA terrain.deck TER.PLT
sep97??19970929121998031800 terrain land use 128x80 terrain land use 82x82 terrain land use 94x94 NA NA NA terrain.deck TER.PLT

Questions and Comments: We're always interested in feedback. Please direct any questions and comments you have to David Ovens (ovens@atmos.washington.edu) or Cliff Mass (cliff@atmos.washington.edu).