The message included below was sent earlier on our communications lines. It is also
posted to the NWS Data Management Change Notices web page at the following URL.
http://weather.gov/datamgmt/notices.shtml 2006/05/30
DM 03-06.07 MAJOR PRODUCT CHANGES TO NCEP GLOBAL ENSEMBLE OUTPUT.
NOXX10 KWBC 162115
DATA MGT MESSAGE 03-06.07
TO AWIPS/NOAAPORT USERS.. FAMILY OF SERVICES/FOS/SUBSCRIBERS...
EMERGENCY MANAGERS WEATHER INFORMATION NETWORK /EMWIN/
NATIONAL WEATHER SERVICE /NWS/ CUSTOMERS... WAFS USERS...
GTS USERS... NWS FAX CHART USERS
FROM RTH WASHINGTON DATA MANAGEMENT
EFFECTIVE DATE MAY 30 2006
MAJOR PRODUCT CHANGES TO NCEP GLOBAL ENSEMBLE OUTPUT -- PLEASE READ CAREFULLY
Starting with the 12 UTC cycle on 30 May 2006 NCEP Central Operations will implement
changes to the
global ensemble processing that will result in drastic changes to its products.
These changes are
necessary to allow us to:
1. Streamline our ensemble processing
2. Provide additional ensemble members at higher resolutions on public servers
3. Eliminate redundant global ensemble products on these servers.
These changes will impact products available on both the NCEP ftp server
(ftpprd.ncep.noaa.gov/pub/data/) and the NWS ftp server
(tgftp.nws.noaa.gov/SL.us008001/ST.opnl/).
Users of these products will need to modify their automated retrieval and processing
routines so that
they can continue to receive and use these data.
The nature of these changes are as follows:
1. Directory Structure - [Affects both the NCEP and NWS ftp servers]
The directory tree of global ensemble data will be drastically changed to allow
for better system
performance on the NCEP Central Computer System (CCS). This change is being brought
to the NCEP and
NWS ftp servers as it will help with both access times and directory listings.
1A. On the NCEP ftp server the directories will change as follows:
Current - ftpprd.ncep.noaa.gov/pub/data/nccf/com/mrf/prod/ens.{YYYYMMDD}
New -
ftpprd.ncep.noaa.gov/pub/data/nccf/com/gens/prod/gefs.{YYYYMMDD}/{CC}/{FILE_TYPE}
where YYYYMMDD is the current date, CC is the cycle time (00, 06, 12, or 18),
and FILE_TYPE is a
descriptor for the type of data files contained in the subdirectory. Examples of
FILE_TYPE that will
be on the NCEP ftp server include: pgrba, pgrbb, ensstat, and wafs.
Users who use the standard pressure GRIB files (ens*.pgrbf*) files on the NCEP
ftp server will be
able to access these data from one of the following locations:
ftpprd.ncep.noaa.gov/pub/data/nccf/com/gens/prod/gefs.{YYYYMMDD}/{CC}/pgrba/
or
ftpprd.ncep.noaa.gov/pub/data/nccf/com/gens/prod/gefs.{YYYYMMDD}/{CC}/pgrbb/
The exact location of the parameters you may need is given in item 3 below.
Users of the ensemble data on WAFS grids will be able to access these at:
ftpprd.ncep.noaa.gov/pub/data/nccf/com/gens/prod/gefs.{YYYYMMDD}/{CC}/wafs/
1B. On the NWS ftp server (tgftp.nws.noaa.gov) the directories will change as
follows:
Current -
tgftp.nws.noaa.gov/SL.us008001/ST.opnl/MT.ensg_CY.{CC}/RD.{YYYYMMDD}/PT.grid_DF.gr1/
New -
tgftp.nws.noaa.gov/SL.us008001/ST.opnl/MT.ensg_CY.{CC}/RD.{YYYYMMDD}/PT.grid_DF.gr1_RE.high/
-
tgftp.nws.noaa.gov/SL.us008001/ST.opnl/MT.ensg_CY.{CC}/RD.{YYYYMMDD}/PT.grid_DF.gr1_RE.low/
The exact location of the parameters you may need is given in item 3 below.
2. Six hourly output - [Affects both the NCEP and NWS ftp servers]
The global ensemble data sets will begin to be available in 6-hour increments
out through 384
hours. Currently 6-hour increment data are only available to 84 hours, then data
are available in
12-hour increments to 384 hours.
3. Break Up of Pressure GRIB data sets (pgrb files) - [Affects both the NCEP and
NWS ftp servers]
To facilitate the removal of redundant data sets the individual member ensemble
files are being
broken up into two files per time step. The first file will contain all of the
parameters currently
contained in the enspost format files (see Item 6 below) at one degree resolution
out to 384 hours.
These are being termed the A files and this is an increase in their resolution for
the 90 to 384 hour
time period. The second set (the B files) will contain the rest of the parameters
at one degree
resolution to 84 hours and 2.5 degree resolution from 90 to 384 hours. This is the
same resolution
that these parameters are currently made available.
On the NCEP ftp server, files will change as follows:
Current -
ftpprd.ncep.noaa.gov/pub/data/nccf/com/mrf/prod/ens.{YYYYMMDD}/ensp1.t{CC}z.pgrbf24
New -
ftpprd.ncep.noaa.gov/pub/data/nccf/com/gens/prod/gefs.{YYYYMMDD}/{CC}/pgrba/gep01.t{CC}z.pgrbaf24
and
-
ftpprd.ncep.noaa.gov/pub/data/nccf/com/gens/prod/gefs.{YYYYMMDD}/{CC}/pgrbb/gep01.t{CC}z.pgrbbf24
On the NWS ftp server, the files will change as follows:
Current -
tgftp.nws.noaa.gov/SL.us008001/ST.opnl/MT.ensg_CY.{CC}/RD.{YYYYMMDD}/PT.grid_DF.gr1/fh.0024_pa.membrp0
1_tl.press_gr.onedeg
New - For the "A" files:
tgftp.nws.noaa.gov/SL.us008001/ST.opnl/MT.ensg_CY.{CC}/RD.{YYYYMMDD}/PT.grid_DF.gr1_RE.high/fh.0024_pa
.membrp01_tl.press_gr.onedeg
- For the "B" files:
tgftp.nws.noaa.gov/SL.us008001/ST.opnl/MT.ensg_CY.{CC}/RD.{YYYYMMDD}/PT.grid_DF.gr1_RE.low/fh.0024_pa.
membrp01_tl.press_gr.onedeg
This change will allow for a subset of higher resolution (one degree) data to be
available out to
180 hours, whereas today it is only available to 84 hours. Parameter lists for the
"A" and "B" files
are located at:
http://www.nco.ncep.noaa.gov/pmb/changes/gefs_20060530_Alist and
http://www.nco.ncep.noaa.gov/pmb/changes/gefs_20060530_Blist
4. File Names Changing due to new ensemble transform mechanism - [Affects both the
NCEP and NWS ftp
servers]
When this change is implemented, NCEP will be creating perturbations in its
ensemble members via a
ensemble transform breeding method. [For specific information about this change,
please see
http://wwwt.emc.ncep.noaa.gov/gmb/yzhu/html/ENS_IMP.html] Under this method, there
will no longer be
positive and negative pairs of ensemble members. NCEP will therefore cease
identifying its members as
either positive or negative and instead use positive numbers for member
identification. For example,
on the NCEP ftp server:
Current -
ftpprd.ncep.noaa.gov/pub/data/nccf/com/mrf/prod/ens.{YYYYMMDD}/ensn1.t{CC}z.pgrbf24
New -
ftpprd.ncep.noaa.gov/pub/data/nccf/com/gens/prod/gefs.{YYYYMMDD}/{CC}/pgrba/gep01.t{CC}z.pgrbaf24
and/or
-
ftpprd.ncep.noaa.gov/pub/data/nccf/com/gens/prod/gefs.{YYYYMMDD}/{CC}/pgrbb/gep01.t{CC}z.pgrbbf24
The names of these files will range from gep01 to gep{NN}, where NN is the
number of ensemble
members. A low resolution control run will be added for all cycles and will be
named as gec00.t{CC}z.*.
On the NWS ftp server, the names will change as follows:
Current -
tgftp.nws.noaa.gov/SL.us008001/ST.opnl/MT.ensg_CY.{CC}/RD.{YYYYMMDD}/PT.grid_DF.gr1/fh.0024_pa.membrn01_
tl.press_gr.onedeg
New - For the "A" files:
tgftp.nws.noaa.gov/SL.us008001/ST.opnl/MT.ensg_CY.{CC}/RD.{YYYYMMDD}/PT.grid_DF.gr1_RE.high/fh.0024_pa
.membrp01_tl.press_gr.onedeg
- For the "B" files
tgftp.nws.noaa.gov/SL.us008001/ST.opnl/MT.ensg_CY.{CC}/RD.{YYYYMMDD}/PT.grid_DF.gr1_RE.low/fh.0024_pa.
membrp01_tl.press_gr.onedeg
The names of these new files will range from fh.{FFFF}_pa.memberp01.* to
fh.{FFFF}_pa.memberp{NN}.*, where NN is the number of ensemble members. The control
run for all
cycles will be named as fh.{FFFF}_pa.memberc00.*.
5. Renaming and restructuring Ensemble mean files (enstat.*) - [Affects NCEP ftp
server only]
The ensstat.* files on the NCEP ftp server will no longer be available. These
grids contain
ensemble mean and spread information for a single parameter for all ensemble members
and all forecast
hours. They will instead be replaced by files that contain multiple parameters for
a single ensemble
member and a single forecast hour. With this configuration the creation of these
data will be made
while the ensemble members are running on the NCEP CCS. Currently these are not
available until the
end of the ensemble run which creates a large amount of data to download at
once.
The current data sets are named as follows:
ftpprd.ncep.noaa.gov/pub/data/nccf/com/mrf/prod/ens.{YYYYMMDD}/ensstat.t{CC}z.{Parameter-name}
The new data sets will be named as follows:
ftpprd.ncep.noaa.gov/pub/data/nccf/com/gens/prod/gefs.{YYYYMMDD}/{CC}/pgrba/geavg.t{CC}z.pgrbaf{FFF}
and
ftpprd.ncep.noaa.gov/pub/data/nccf/com/gens/prod/gefs.{YYYYMMDD}/{CC}/pgrba/gespr.t{CC}z.pgrbaf{FFF}
6. Removal of enspost, and ensemble Data Files - [Affects both the NCEP and NWS ftp
servers]
To reduce product redundancy and to allow for the additional data sets outlined
in items number 2
and 3 above, the enspost.* (fh.xxxx.* files at NWS ftp) and ensemble.* data sets
will no longer be
produced. These data sets contain redundant information that is already available
in the pressure
GRIB data sets. They are being removed and users should instead use the "A" files
located on the NCEP
ftp server at:
ftpprd.ncep.noaa.gov/pub/data/nccf/com/gens/prod/gefs.{YYYYMMDD}/{CC}/pgrba/ge{NNN}.t{CC}z.pgrbaf{FFF}
(where NNN is the member name, c00, p01-p10) and on the NWS ftp server at:
tgftp.nws.noaa.gov/SL.us008001/ST.opnl/MT.ensg_CY.{CC}/RD.{YYYYMMDD}/PT.grid_DF.gr1_RE.high/fh.{FFFF}_
pa.membr{NNN}_tl.press_gr.onedeg
Even though these new "A" grids contain the same information as the enspost.*
(fh.xxxx.* files at
NWS ftp) and ensemble.* data sets, they are organized differently. The existing
files are created at
the end of the ensemble processing and each file contains information for a single
parameter for all
ensemble members and all forecast hours. The new "A" files will be made available
throughout the
production time of the ensemble processing on the NCEP CCS and they will each
contain multiple
parameters for a single ensemble member and a single forecast hour.
There is one exception to this change. The 24-hour bias corrected ensemble
products created at 00
UTC and available only the NCEP ftp server, will continue to be made available in
the following new
location:
ftpprd.ncep.noaa.gov/pub/data/nccf/com/gens/prod/gefs.{YYYYMMDD}/{CC}/ensstat/ensstat.pqpf_24h
and
ensstat.pqpf_24hbc
7. Corrected ensemble extensions in GRIB1 PDS - [Affects both the NCEP and NWS ftp
servers]
The current global ensemble data sets do not properly use the extended Product
Definition Section
(PDS) of GRIB1. When this change is implemented the GRIB1 data will be correctly
labeled as ensemble
data sets. This information is given in PDS octets 41 and higher. A description of
NCEP's use of
these octets is given at:
http://www.nco.ncep.noaa.gov/pmb/docs/on388/appendixc.html
8. Removal of all GRIB index files - [Affects both the NCEP and NWS ftp
servers]
The GRIB index files are no longer required by NCEP production and are being
removed from the ftp
servers. These files are currently named as follows:
NCEP -
ftpprd.ncep.noaa.gov/pub/data/nccf/com/mrf/prod/ens.{YYYYMMDD}/ens{NN}.t{CC}z.pgrbif24
NWS -
tgftp.nws.noaa.gov/SL.us008001/ST.opnl/MT.ensg_CY.{CC}/RD.{YYYYMMDD}/PT.grid_DF.gr1/fh.{FFFF}i_pa.memb
r{NNN}_tl.press_gr.{XXX}deg
If users still need GRIB index files, they can be created with NCEP software
located at:
http://www.nco.ncep.noaa.gov/pmb/codes/nwprod/util/sorc/grbindex.fd/
9. Removal of the 12 UTC "e2" Member -- Addition of Low Resolution Control Run for
all Four Cycles
With this implementation all four cycles per day will have a low resolution
control run. The need
for the "e2" member at 12 UTC will go away at that time. The NCEP CCS resources
that were used to run
the "e2" member will be used for the low resolution control member. The low
resolution control member
data will be found at:
ftpprd.ncep.noaa.gov/pub/data/nccf/com/gens/prod/gefs.{YYYYMMDD}/{CC}/pgrba/gec00.t{CC}z.pgrbaf{FFF}
and
ftpprd.ncep.noaa.gov/pub/data/nccf/com/gens/prod/gefs.{YYYYMMDD}/{CC}/pgrbb/gec00.t{CC}z.pgrbbf{FFF}
10. 6-hour Accumulations for Precipitation and Maximum and Minimum Temperature
In the current global ensemble system accumulation variables alternate between
6-hour and 12-hour
amounts depending upon the forecast hour. With this upgrade all accumulation
amounts will be based on
a 6-hour period.
TEST DATA:
At this time we are not able to provide parallel global ensemble data sets for user
to compare the old
versus new. We are however able to provide a static data set. These data can be
viewed at:
ftpprd.ncep.noaa.gov/pub/data1/nccf/com/gens/prod/gefs.20060306/
note that these static data are located under /pub/data1 not /pub/data.
It is anticipated that we will be able to establish a real time feed of the parallel
data sets by the
end of March 2006. Once this parallel feed of the new ensemble data sets is
available, a new message
will be sent out via this mechanism.
Please direct any questions on these changes to:
NCEP.List.PMB-PCSP@xxxxxxxx
FOR FOS/NOAAPORT AND NON-AWIPS CUSTOMERS - IF YOU HAVE ANY
QUESTIONS REGARDING ROUTING OR WOULD LIKE TO ADD THESE
PRODUCTS TO YOUR DATASTREAM PLEASE CONTACT.
Data Management
EMail nws.dm@xxxxxxxx
THIS INFORMATION IS ALSO POSTED ON THE NWS DATA MANAGEMENT CHANGE
NOTICES WEB PAGE. THE URL IS LISTED BELOW.
http://weather.gov/datamgmt/index.html DATA MANAGEMENT
TELECOMMUNICATION OPERATIONS CENTER
RTH WASHINGTON SENDS
--
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needs for information. The URL address for our CRM System
is listed below.
http://help.nws.noaa.gov/cgi-bin/doit.cgi?201~-506,,,,1:467:1
