Information about Reanalysis Data

Historical cases are ran using NCEP/NCAR Global Reanlysis I and II (NNRP) datasets obtained from the NWS SOO Science and Technology Resource Center’s EMS servers. Reanalysis data were available from the EMS for the 1948 to 2006 time period (1948-1979 for Analysis I and 1980 to 2006 for Analysis II). See NWS SOO Science and Technology Resource Center for more details about the EMS WRF package and EMS User Guide to learn how to run historical case studies using reanalysis data. For more information about the NCEP/NCAR Global Reanalysis Data, click here.

Source of NCEP/NCAR Global Reanalysis Dataset:
Kalnay et al.,The NCEP/NCAR 40-year reanalysis project, Bull. Amer. Meteor. Soc., 77,
437-470, 1996.

The reanalysis data for the historical cases were ran on a custom 36 km grid covering the Continental United States, much of Canada and Mexico, and some of the adjacent waters of the Atlantic Ocean, Pacific Ocean, Gulf of Mexico, and Caribbean Sea. The model was custom ran using the parameterizations specified below.


Caution must be used when examining these historical data. The use of reanalysis data combined with custom specified parameterizations and grid spacing does not allow for an exact meteorological representation of the historical events. As you will see, in some cases the strength and location of meteorological features including low pressure systems vary (sometimes significantly) from the verified observations. Varying the model parameterizations specified below and grid spacing would likely result in changes in the model output. Therefore, the historical events depicted are not exact representations of reality. These historical cases are simply presented to gain a general idea of the meteorological patterns and atmospheric conditions that led to the development and evolution of these historical meteorological events.

Particulars & Parameterization:

  • 36km Horizontal grid spacing over much of North America
  • Kain-Fritsch cumulus scheme (Kain (2004, JAM))
  • Lin et al. Microphysics Scheme (Lin et al. 1983; Rutledge and Hobbs 1984; Tao et al. 1989; Chen and Sunn 2002)
  • Yonsei University PBL Scheme (Skamarock et al. 2005)
  • Noah MP Land Surface Model (Chen and dudhia, 2001)
  • RRTM Longwave Radiation Scheme (Mlawer et al 1997)
  • Dudhia Shortwave Radiation Scheme (dudhia 1989)