NCEP North American Regional Reanalysis: NARR

Main Page | Pressure | Monolevel | Subsurface

See the PSL NARR webpage for more information on PSL's involvement in the NARR project

Brief Description:

• Very High Resolution Reanalysis of the North American region including assimilated precipitation.

Temporal Coverage: 8-times, Daily and Monthly means for 1979/01/01 to Feb 28, 2021 . Spatial Coverage: The native model grid is converted to a Northern Lambert Conformal Conic grid which is what we archive. Corners of this grid are 12.2N;133.5W, 54.5N; 152.9W, 57.3N; 49.4W ,14.3N;65.1W (essentially, North America). The grid resolution is 349x277 which is approximately 0.3 degrees (32km) resolution at the lowest latitude. A page describing the coverage along with information on reading the projection is available.

Levels:

• 5 levels:
  0 , 10 , 40 , 100 cm for all variables plus 800cm for soil temperature.

Update Schedule:

• Irregular.

Data Caveat: The data for 2003-2004 were re-done, after a processing error at NCEP, and the data for 2005 through 2006/06 were added. However, a caveat: From 12Z 10 Feb., 2004, through 21Z 10 Feb., 2004, and 0Z 24 Feb., 2004 through 9Z 24 Feb., 2004, the following variables seem wrong - wcconv and wvconv are a couple of orders of magnitude wrong in both extrema; a large number of spatial points are off (most of them). ULWRF at the top of the atmosphere (ulwrf.ntat) seems to have oddly low minima for these same eight time steps. Not so many spatial points are affected with this variable, however ( less than 1 percent).

Download/Plot Data: (Download Issues) Pressure Level Data

Variable	Statistic	Level	Download File	Create Plot/Subset
Soil Temperature	3-hourly value	0-800cm	tsoil.yyyymm.nc	N/A
Soil Temperature	Daily Mean	0-800cm	tsoil.yyyymm.nc	N/A
Soil Temperature	Monthly Mean	0-800cm	tsoil.mon.mean.nc	N/A
Liquid Volumetric Soil Moisture (non-frozen) Fraction	3-hourly value	0-100cm	soill.yyyymm.nc	N/A
Liquid Volumetric Soil Moisture (non-frozen) Fraction	Daily Mean	0-100cm	soill.yyyymm.nc	N/A
Liquid Volumetric Soil Moisture (non-frozen) Fraction	Monthly Mean	0-100cm	soill.mon.mean.nc	N/A
Volumetric Soil Moisture (frozen + liquid) Fraction	3-hourly value	0-100cm	soilw.yyyymm.nc	N/A
Volumetric Soil Moisture (frozen + liquid) Fraction	Daily Mean	0-100cm	soilw.yyyymm.nc	N/A
Volumetric Soil Moisture (frozen + liquid) Fraction	Monthly Mean	0-100cm	soilw.monmean.nc	N/A

Also Available Plotting Pages:

• Monthly/Seasonal Composites
• Daily Composites
• 3-Hourly Composites

Usage Restrictions:

• None

Detailed Description:

• The NARR project is an extension of the NCEP Global Reanalysis which is run over the North American Region. The NARR model uses the very high resolution NCEP Eta Model (32km/45 layer) together with the Regional Data Assimilation System (RDAS) which, significantly, assimilates precipitation along with other variables. The improvements in the model/assimilation have resulted in a dataset with substantial improvements in the accuracy of temperature, winds and precipitation compared to the NCEP-DOE Global Reanalysis 2. For a complete list of model output variables, see NCEP's variable list.
• Additional information can be found at NCEP's NARR page.

Caveats:

• Useful information can be found at NCEP's NARR FAQ page and from Albany's Department of Atmospheric Science NARR Usage Notes.

Related File Naming & Structure Information:

File Names:

• 8-times daily and daily File names are composed of variable abbreviations and year/month: (variable).(year)(mm).nc(In directory: /Datasets/NARR/ or /Datasets/NARR/Dailies/)
• Monthly means/ltms are (variable).mon.mean.nc in /Datasets/NARR/Monthlies/

Dataset Format and Size:

• All data are stored in PSL standard NetCDF files.
• The data are divided by variable and year and month into separate files
• There are 2100 files currently
• Size of file is about 1.4G per variable per year/month for 8xdaily data
• Size of file is about 68M per variable per /month for monthly data
• Current total of 29.4 Tbytes for 8xDaily.

• 8x daily data are available from ftp.cdc.noaa.gov in /Datasets/NARR/.
• The 8x data files are quite large, so you may only be able to download them if you have a fast network connection.

Missing Data:

• Missing data is flagged with a value of 9.96921e+36f.

Citation:

• Please note: If you acquire NARR data products from PSL, we ask that you acknowledge us in your use of the data. This may be done by including text such as NARR data provided by the NOAA/OAR/ESRL PSL, Boulder, Colorado, USA, from their Web site at / in any documents or publications using these data. We would also appreciate receiving a copy of the relevant publications. This will help PSL to justify keeping the NARR data set freely available online in the future. Thank you!
• NORTH AMERICAN REGIONAL REANALYSIS: A long-term, consistent, high-resolution climate dataset for the North American domain, as a major improvement upon the earlier global reanalysis datasets in both resolution and accuracy, Fedor Mesinger et. al, submitted to BAMS 2004.

References:

• NORTH AMERICAN REGIONAL REANALYSIS: A long-term, consistent, high-resolution climate dataset for the North American domain, as a major improvement upon the earlier global reanalysis datasets in both resolution and accuracy, Fedor Mesinger et. al, submitted to BAMS 2004.

Original Source:

• Dataset was originally produced at NOAA's National Center for Atmospheric Prediction (NCEP) and is available in it's original grib format through NOAA NCDC's access page. It is also available in the same format from NCAR.

Contact:

• Physical Sciences Laboratory: Data Management
  NOAA/ESRL/PSL
  325 Broadway
  Boulder, CO 80305-3328
  psl.data@noaa.gov