NOUS41 KWBC 151304 AAC
PNSWSH
Technical Implementation Notice 10-55,
Amended
National Weather Service Headquarters
Washington DC
905 AM EDT Tue Mar 15
2011
To:
Subscribers:
-Family of Services
-NOAA Weather Wire Service
-Emergency Managers Weather Information Network
-NOAAPORT
Other NWS Partners, Users and Employees
From: Timothy
McClung
Chief, Science Plans Branch
Office of Science and Technology
Subject: Amended: Climate
Forecast System (CFS) Changes:
Effective Date Scheduled for March 30, 2011.
Amended to set the
implementation date as Wednesday March 30, 2011.
Effective Wednesday, March 30, 2011,
beginning with the 1200
Coordinated Universal Time (UTC), the
National Centers for Environmental Prediction (NCEP) will upgrade the CFS. All
components of the CFS--the atmospheric model, ocean model, land-surface model,
and data assimilation--will be upgraded as part of this change.
Users must upgrade their process of
obtaining CFS data as there will be major changes in content, format, volume of
data and data dissemination source with this upgrade.
NCEP will continue to run the current version
of the CFS
A 3-layer interactive global sea ice model,
as well as a global
land data assimilation will be introduced to the CFS. The resolution of the
atmospheric forecast model will be increased from T62 (210 km) to T126 (100
km). The ocean forecast model will be upgraded from the limited area GFDL MOM3
to the global MOM4. The horizontal resolution will increase from 0.33 degree to
0.25 degree from 10 North to 10 South latitudes. Northwards and southwards to
the poles, the resolution will increase from land model. For more details on the upgrades to the forecast model and products,
please check the CFS website at:
http://cfs.ncep.noaa.gov/cfsv2.info
The data assimilation for the Climate
Forecast Model will also be upgraded. The resolution of the Atmospheric Climate
Data Assimilation Version 2 (CDAS2) will be upgraded from T62
http://cfs.ncep.noaa.gov/cfsv2.info
There will be significant additions to
parameters in the pressure grib (PGRB), flux files (FLX)
and ocean (OCN) files. In addition, there will be a new file that contains
parameters on isentropic surfaces (IPV).
Due to the increases in resolution, there
will be significant changes to the format, content and sizes of all these
files. The horizontal resolution of PGRB files will increase from 2.5 x 2.5
degree to 1 x 1 degree and the number of pressure levels will increase from 17
to 37. The size of the flux file will increase from the Gaussian grid for T62
(192X94) to that for T126 (384X190). The ocean file will increase from 2.5 x
2.5 degree to 0.5 x 0.5 degree. The new isentropic file will have a resolution
of 1 x 1 degree. There will also be an increase in the temporal resolution of
the output forecast data, from 12-hourly to
6-hourly. For more detailed information about changes/additions to these files, please
check the CFS website at:
http://cfs.ncep.noaa.gov/cfsv2.info
Another significant change will be the
discontinuance of all seasonal products, both for the real time forecasts and climatologies. Only monthly mean products
will be disseminated.
A set of test data is available at the CFS
website at:
http://cfs.ncep.noaa.gov/cfsv2.info
The current CFS output is disseminated via
both the NWS FTP server and the NCEP server. With this upgrade, there
will no longer be CFS output disseminated from the NWS FTP server at:
ftp://tgftp.nws.noaa.gov/SL.us008001/ST.opnl/
in the MT.cfs_MR.clim or MT.cfs_MR.fcst directories. All CFS
output, along with the climatologies,
will be made available only on the NCEP server and NOMADS. Beginning on March
30, 2011, CFS output from the current day will be available via http and ftp
at:
http://www.ftp.ncep.noaa.gov/data/nccf/com/cfs/prod
and
ftp://ftp.ncep.noaa.gov/pub/data/nccf/com/cfs/prod
CFS output from the previous 7 days will be
available
http://nomads.ncep.noaa.gov/pub/data/nccf/com/cfs
Data delivery timing of the CFS will be
changed by this implementation. The new CFS will run longer than the
current CFS, and therefore disseminate the products at a later time.
A consistent parallel feed of data has been
available on the NCEP server since late December 2010, at the following URL:
http://www.ftp.ncep.noaa.gov/data/nccf/com/cfs/para/
and
ftp://ftp.ncep.noaa.gov/pub/data/nccf/com/cfs/para/
NCEP encourages all users to ensure their
decoders are flexible and are able to adequately handling changes in content,
changes in the scaling factor component within the product definition section
(PDS) of the GRIB files, and any volume changes which may occur.
If you have any questions concerning these
changes, please contact:
Suranjana Saha
NCEP/Global Climate and Weather
Modeling Branch
Camp Springs , Maryland
301-763-8000 X 7236
or
Shrinivas Moorthi
NCEP/Global Climate and Weather
Modeling Branch
Camp Springs , Maryland
301-763-8000 X 7233
NWS National Technical Implementation
Notices are online at:
http://www.nws.noaa.gov/os/notif.htm
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