NCEP ENSEMBLE GRIB DATA INFO
Information on this page:
Other relevant information:
Fast Downloading of GRIB Files (partial http transfers)
Updated documentation for ensemble data information
Getting NCEP Ensemble data via anonymous ftp
NCEP Ensemble data are currently available via anonymous ftp on 3 different servers:
NCEP anonymous ftp server
Typically, the NCEP ftp server will have a few recent days worth of
on-line, while the NWS server will only have the data for the current
The data are grouped together according to variable. For example, the
enspost.T00Z.z500 will contain all 12 ensemble perturbation forecasts
500 mb height for 00z for the day given by the directory name. The
variables are available in this file:
Listing of the Current Ensemble Grib Inventory on the NCEP ftp server.
NWS Gateway operational anonymous ftp server
(ftp://tgftp.nws.noaa.gov/SL.us008001/ST.opnl/, see MT.ensg_CY.00/ and/or MT.ensg_CY.12/)
NCEP NOMADS (latest) Plots, data, points of contact, details, and a web interface for the data.
NCEP NOMADS for non-operational CMC bias corrected ensemble forecast Plots, data, points of contact, details, and a web interface for the data.
NCEP NOMADS (Server 5) Plots, data, points of contact, details, and a web interface for the data.
Mirror for NCEP NOMADS Server 5.
Parties interested to establish a dedicated ftp line to
forecast data should contact Julie Hayes
headquarters and ask for information on "SAS" lines.
For each variable, 1 file is written for the 12 00z perturbations and 1
file is written for the 5 12z perturbations. In each file and for each
perturbation, data are included every 12 hours from valid time = 00h to
384h. GRIB index files are also included on these servers in the same
as the GRIB data files, and are identified by the "i" after the
identifier in the file name (e.g., enspost.T00Z.z500i ).
precipitation probabilities (ensspf)
mean sea level pressure (prmsl)
rh 700 mb (rh700)
T 2 meters (t2m)
T Max, T Min (tmax, tmin)
T 850 mb (t850)
u-comp 10 meters, v-comp 10 meters (u10m, v10m)
u-comp 250 mb, v-comp 250 mb (u250, v250)
u-comp 500 mb, v-comp 500 mb (u500, v500)
u-comp 850 mb, v-comp 850 mb (u850, v850)
250 mb gp height (z250)
500 mb gp height (z500)
850 mb gp height (z850)
1000 mb gp height (z1000)
In addition, a file containing probabilistic
quantitative precipitation forecasts (PQPF), derived from the
is also available.
FTP Access to NCEP
You can find NCEP GRIB decoding software at the following location:
The NCEP ftp server:
Take a look at the README file. Read that and then cd to the
to download the software.
*** You can find help
using NCEP's GRIB
software by clicking
GRIB PDS extension
NCO maintains a web document describing the format of the NCEP GRIB
section for ensembles:
USE OF THE EXTENDED GRIB PDS SECTION
FOR DESCRIBING ENSEMBLE OUTPUT