About NOAA CORe Reanalysis

Overview

CORe is a climate atmospheric reanalysis from 1950-present. Like all reanalyses, it produces a 3D physically constrained representation of the atmosphere for each model output time, using "assimilated" observations. CORe replaces the real-time extension of the NCEP/NCAR Reanalysis (1948-present).

Like the NCEP/NCAR Reanalysis extension, CORe is an atmospheric reanalysis that uses externally produced Sea Surface Temperature (SST), sea ice, and snow analyses for boundary conditions. However, COREe uses more modern versions of these analyses. It also differs in that it uses little of the satellite data as input so there is no strong discontinuity in climate/weather processes in the modern satellite era.

Data Access

Technical information about the NOAA CORe files follows. Please note: For questions on the CORe model, output, and how to get it, please contact NOAA/NCEP. PSL is not involved in CORe production but is providing these technical details as a service to our users.

Scientific and technical enhancements

CORe is a UFS-based system (circa 2020 codes) which uses an Ensemble Kalman filter to assimilate conventional observations as well as Atmospheric Motion Vectors (AMV). CDAS is a MRF-based system (circa 1995 operational codes) that assimilates conventional observations, as well as AMV and satellite temperature retrievals.

The data files for CORe will be available on the NOAA Operational Model Archive and Distribution Service (NOMADS) at the following location: https://nomads.ncep.noaa.gov/pub/data/nccf/com/core/

The data files for CDAS will no longer be available as of March 9, 2026 at the following locations:

  https://nomads.ncep.noaa.gov/pub/data/nccf/com/cdas/
  ftp://ftp.ncep.noaa.gov/pub/data/nccf/com/cdas/

  https://nomads.ncep.noaa.gov/pub/data/nccf/com/cdas2/
  ftp://ftp.ncep.noaa.gov/pub/data/nccf/com/cdas2/
  

Sample CORe files are available at the following location:

https://nomads.ncep.noaa.gov/pub/data/nccf/com/core/para/

At the provided CORe URL, new CORe files have the following paths and regexes:

/core.YYYYMMDD/HH/post/flx/core.tRRz.flx.memMMM[.grib2,.grib2.idx]
/core.YYYYMMDD/HH/post/flx/core.tRRz.flx.ensmean[.grib2,.grib2.idx]
/core.YYYYMMDD/HH/post/flx_stats/core.tRRz.flx.ensstats[.grib2,.grib2.idx]
/core.YYYYMMDD/HH/post/nceppost/core.tRRz.pgb.ensmean.anl[.grib2,.grib2.idx]
/core.YYYYMMDD/HH/post/nceppost/core.t[HH+06]z.pgb.ensmean.f003[.grib2,.grib2.idx]
/core.YYYYMMDD/HH/post/spost/core.tRRz.spgb.memMMM.anl[.grib2,.grib2.idx]
/core.YYYYMMDD/HH/post/spost/core.tRRz.spgb.ensmean.anl[.grib2,.grib2.idx]
/core.YYYYMMDD/HH/post/spost_stats/core.tRRz.spgb.ensstats[.grib2,.grib2.idx]

where YYYYMMDD is the date, HH is the forecast cycle (00,06,12,18), RR is the hour of the reference time (forecast cycle + [03,06]), and MMM is the ensemble member (001-080 inclusive).

The grib version 1 files have been replaced by grib version 2.