MM5/WRF World Wide Data

MM5/WRF are widely-used three-dimensional numerical meteorological models which contain non-hydrostatic dynamics, a variety of physics options for parameterizing cumulus clouds, microphysics, the planetary boundary layer and atmospheric radiation. MM5/WRF have the capability to perform Four Dimensional Data Assimilation (FDDA), and are able to simulate a variety of meteorological phenomena such as tropical cyclones, severe convective storms, sea-land breezes, and terrain forced flows such as mountain valley wind systems.
MM5 vs WRF
The WRF model is a newer model with updated physics schemes. Studies have shown the WRF model to have less smoothing, which can allow smaller scale features such as terrain effects to affect the solution. The WRF model has also been shown to provide equal or better forecasts than those of the MM5 model. For more information click here.

In order to facilitate the use of advanced non-steady-state air quality modeling techniques such as CALPUFF in areas with sparse or no meteorological observations, TRC is making available MM5/WRF datasets in two formats:
Tiled Data Format: Convenient small portions of data and may be ordered in as many (or as few) as you need to cover your domain of interest. Tiles can be converted to CALMET-ready 3D.DAT files using extraction software provided with the data set. This format is intended for CALMET use only.  Each tile covers an area of 10 x 10 grid points. It includes hourly data for a full year. The time stamp of the data is UTC (GMT) time. Each tile contains 8760 hours (or 8784 hours for a leap year) plus 12 hours of the prior year (in UTC time) and 12 hours of the following year (in UTC time).  The hourly 3-D meteorological parameters included in the tiles are wind speed, wind direction, temperature, pressure, geopotential height, vertical velocity, relative humidity, mixing ratios for water vapor, cloud water, rain, ice and snow. Hourly surface (2-D) parameters in the tiles include sea-level pressure, rainfall amount, snow cover, short wave and long wave radiation at the surface, air temperature at 2m, specific humidity at 2m, wind speed and wind direction at 10m and sea surface temperature. There are 52,000 3-D data points per hour and 1,000 2-D data points per hour included in each tile. Each tile contains one year of data in a packed (compressed) format that is roughly 450 MB in size.
Native Binary Output Format: The ideal file format when data needs to be used for applications other than CALMET (for example: grid modeling). The binary data is provided on a domain-wide basis only. MMOUT files from MM5 and WRFOUT files from WRF can be converted to CALMET-ready 3D.DAT files using the CALMM5 or CALWRF preprocessing programs respectively.
All MM5/WRF Data Sets have been classified into six (6) world region groups, roughly corresponding to the continents. For more information, including available data sets and ordering information, please click on the links below. 


If you already know what you want, please fill out the



If you cannot find the specific area or year you are looking for.


Not sure what tile or domain is needed?  Please click on the button below to use the "Tile Selector" Application.  Note: Before you begin, please read the "Tile Selector Help" document for instructions on installing and using this application.   

CALMET can be run in "No-Observations Mode" with no other meteorological data other than the MM5/WRF data, or it can be run in "Hybrid Mode" using observations together with the MM5/WRF dataset (CALMET can also be run in an "Observations Only" mode using only observational data.).  CALMET contains algorithms to compute the cloud cover and ceiling height for each CALMET grid point from the relative humidity and liquid water data contained in the MM5/WRF dataset.


Hourly Time Resolution, Horizontal Grid Spacing, 3-D Variables and 2-D Variables
Horizontal grid spacing: 12 km (4 km or 1.33 km for higher resolution data). 40 vertical half-sigma levels. The nominal heights above the ground at a MM5/WRF grid depend on its surface elevation. The nominal heights listed below are for a grid location at sea level.
Below 100 meters: 1, 34, 60, 90, 123, 160, 202, 250, 304, 365, 434, 511, 600, 700, 814, 944 (meters)
1,000 - 3,500 Meters: 1092, 1262, 1455, 1678, 1934, 2231, 2576, 2980, 3456 (meters)
Above 3,500 Meters 4022, 4628, 5180, 5706, 6265, 6866, 7546, 8317, 9225, 10311, 11427, 12262, 12875, 13547, 14290 (meters)
3-D Variables Include
Wind speed and wind direction, Temperature, Relative Humidity, Pressure, Mixing ratios of water vapors, cloud water, rain water, ice and snow.
2-D Variables Include
Precipitation Amount, Short wave solar radiation, Long wave solar radiation, Snow cover, 2-m temperature and specific humidity, 10-m wind speed and direction, Sea surface temperature
Available Data Formats
Tiled (2 versions) Native Binary (1 version)
  1. Individual Tiles
  2. Full Domain (for use with CALPUFF modeling system)
  1. Full Domain only (for use with models such as CMAQ)
Available Data Storage
Individual tiles are available on either DVD or USB hard drive. The Full Domain dataset is provided on a hard drive only. Be sure to specify the hard drive format on the order form.

External USB Hard Drive - Hard drives provided are USB 2.0 external drives of at least 250 GB capacity up to 2000 GB. The power supply can handle voltage in the range of 100-240V, 50-60Hz but contain a USA-type of electric plug that will require an adapter in other countries (not provided). User-supplied hard drives can be accommodated as a special order. Smaller drives (250 GB) do not require a power supply as these run on USB connection.

DVD Orders - MM5/WRF data will be provided on DVDs, except for the Full Domain, which are available only on hard drives due to the large space requirements of the files.
Easy-to-use software is provided with the tiles to extract the data and create a CALMET-compatible 3D.DAT file. Any rectangular set of tiles can be combined into a 3D.DAT file for input into CALMET. The user selects a range in terms of latitude/longitude or model grid points to be extracted and a time period and the extraction software will identify the tiles needed and perform the data extraction. New tiles can be added to existing tiles to allow the capability to create larger domains in the 3D.DAT files.

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~ Last updated: December 28, 2012~